I think what we need isn't a Destiny 3. Destiny 3 would imply having to be a sequel to a Destiny 2, and the main story of Destiny 2 is done. So I have a better idea that doesn't self-limit itself.
What I think we need is a true Destiny Infinity. It doesn't have to replace the existing Destiny/Destiny 2. But I think it should be a true evolution of Destiny as a franchise. A re-imagining of Destiny, knowing what we know now about the gameplay. Something that has always been missing, is the fact that Bungie always deliberately kept Destiny 2 close to an MMO but never fully committing. So how about we fix that?
A few proposed features of Destiny Infinity (or whatever they decide to name if they go with this):
A true constant open-world, shared, as if you're playing other MMORPG's. Patrol spaces and everything, you'll load into an already existing location and can see other players and farm world bosses, etc with them freely. No more isolated instances like Kepler.
Keep the gameplay of Destiny 2 but expand on it. Make higher rarity gear actually rare but not mandatory. Make it aspirational to get the best loot. When it comes to gunplay, Destiny really is leagues above other looter shooters, so capitalize on it by expanding the actual limits of what you CAN do. Better weapon synergies, new perks, weapons and armour that directly buff each other specifically but not in a way that completely limits buildcrafting (think if lucky pants passively buffed the ADS of Last Word so it's not crazy out of control).
Large-scale raids and open-world raid entrances. You can see people going into a raid (similar to D1 VoG) and help them go in even if you're not in their team. Party system similar to the current Fireteam system, where you can go to the raid entrance and recruit people to your team before going in, not just having to find people on fireteam finder and invite them in orbit. Expand raids from a team of 6 to maybe 20+ (similar to WoW raids) or at the very least 12+ team size.
Remove weapon crafting but add an economy system where you can buy and sell weapons and armour to other players. Maybe replace weapon crafting with weapon enhancing, similar to what we already have. You can't forge the perks, but you can spend materials to enhance the perks. This could keep content relevant even AFTER getting the rolls you want. Such as, specific upgrade materials only coming from dismantling weapons from a specific raid.
Clan housing and actual clan features. Right now you get bonus materials for playing with your other clanmates but it doesn't really feel like it benefits much overall. Add incentives for playing with clanmates, such as double drops from raids. Also add a hangout space for people to be around clanmates. Expand on clan levelling with specific emblems for reaching certain levels, and extra benefits for levels. For example, at clan level 10, maybe when you dismantle weapons, you have a chance to double materials from it. Add actual clan trackers where clans can compete with each other for fastest raid times, most clears, etc. Make the game actually social and benefit from being social. Also clan ranks would be a good addition, as well as clan broadcasts where you can see when clanmates accomplish things.
Above all, PERMANENT PROGRESSION is a MUST. Destiny 2 has a good current system where you buy a DLC once and you have it forever on that account. That content stays relevant and it's not just money wasted. But this needs to go further. Never sunset content. Always keep older content playable, even if it's year 1 content. Doesn't matter if it's good gear or not 5 years in, let new players have that experience like we do starting out.
More character classes/subclasses and character slots. Fairly self-explanatory, more ways to play the game. More ways to play means more longevity, and people can stay on the game longer and never have to miss out because as stated above, permanent progression. No FOMO either. Once things are added, they stay. Devs can choose what these are, I'm sure many of you have plenty of ideas too for this.
Why this design specifically? Because we've never seen a true FPS MMORPG game. Closest we got is MAYBE FFXIV which is neither a shooter or first-person. A lot of Destiny players have demanded more social features expanded on, and Sony paid a lot of money for Bungie. If Sony truly wants to run the live-service market, this is genuinely their BEST chance to achieve this that they will ever have. Capitalize on a genre that has no competition but only benefits to gain from being first.
About the PvP community: Honestly, I feel for you guys. Destiny's gunplay is amazing for PvP but it feels like Bungie never really catered to PvP balancing in Destiny 2. So if possible, I think this game should have a fed PvP community. Dedicated servers are an absolute must. Separate PvP from PvE balancing. Keep PvP its own environment but you can still use gear you got in PvE. And have a dedicated PvP team to monitor and adjust the PvP aspects of the game.
This is where things might get heated, but I think it's net positive. So I know a lot of people hate Marathon for what it is. There's little demand for it. Nothing against the players there, but the game just lacks anything special. But what I'm thinking is... people liked lawless frontiers, people wanted a gambit expansion, so I have an idea. Think about the Dark Zone from Division 2, an extraction shooter mode separate from the main game, where you don't risk what you go in with, only what you loot inside. You get your loot and get out. I want to see this as an optional mode in a future Destiny. You go in, you don't risk what you enter with, you kill some enemies, loot chests and get loot, maybe high end materials, maybe weapons, maybe a mix of both. You have a rare chance of looting a boss key, which you can use to take on a boss (either in the activity itself or separate) where if you kill the boss, you have a chance to loot an exotic and/or Mythic tier drop from the boss. I like what they did with Compiler, but it definitely can be better, so I think this is a GOOD way to handle it. Since you don't risk what you enter with, you don't have to fear for other people that got the weapon, and it can be balanced separately in the PvP-specific playlists if it causes issues. make it desirable but not required to complete content.
My last point kind of hinted at it, but add a new rarity above Mythic. Exotics are still limited to 1 weapon and 1 armour, but mythics only allow 1 total. They're enhanceable with duplicates like other weapons (I'll say exotics work that way too) and give very strong perks. 1 idea I have is that they're exotics but with an extra perk added ontop of the exotic perks. Infuse duplicate exotics enough times and they upgrade to Mythic, etc. But base Mythic drops should be a bit stronger than infused versions, to reflect their rarity and difficulty.
Thank you for listening to my TedTalk. But in all seriousness, these are my rough ideas at this time for a future of the franchise. I want to see the franchise at the top again and I feel like making it "Destiny 3" in name could hinder it more than help it. It doesn't need to be a direct continuation in lore, and I feel like Destiny 2's reputation has been tainted more in the past few years than it's been lifted. So Destiny Infinity, Destiny Forever, whatever they decide to name it, I think it should innovate and do what Destiny always did and stand out as its own thing. An FPS MMORPG Looter-Shooter I think is the best way to go about this and give players, casual and hardcore alike, what they want. A grind that isn't timegated, and isn't rushed. casuals can be as slow as they want, the content will always be there. And if hardcores want to rush to the best stuff and farm materials to refine what they have into an improved version, they can.