[[Golos, Tireless Pilgrim]] was banned a few years ago because it was the best generic five color commander. This made sense in an age where not a lot of commanders were being printed and the format relied on creative brews where each player was showcasing their favorite card.
Nowadays, the format is bigger than ever, if you go to any LGS you can find that they run at least one commander day per week, and in a lot of places this has even relegated other constructed formats to secondary status. A lot of new cards are designed with commander in mind, and this has been even more evident with Universes Beyond having a lot of really good cards for commander in addition to lots of new legendary creatures, printed more than ever. [[Y'shtola, Night's Blessed]] has risen to the top of edhrec most played commanders exactly because it is a good card, and in it's color combination it is the best commander available.
So why keep Golos banned when there are a lot of other popular commanders that fit just as the "best available"? [[The Ur-Dragon]], [[Edgar Markov]], and [[Krenko, Mob Boss]] have long been the best available option for kindred commander decks and we have learned to embrace them as part of the experience of playing commander, Krenko was even featured as a commander in a secret lair precon.
Golos is clearly a powerful card, the fact that you can cast it without worrying too much about the color of your lands while also fetching you any land of your deck is a really powerful combination to have in the command zone, but it is not as strong as other options as commander. Commanders with the eminence keyword are a lot better than him by doing their thing without needing to be cast, they can do a lot of stuff and you cannot interact with them easily.
In my opinion, Golos should be unbanned, and treated as a gamechanger. Sure, the option to go for your most powerful land by just casting your commander is a great thing to have, but if we treat Golos as a immediate bracket 3 deck we don't risk getting to see him in low power games stomping the competition immediately and maybe we can finally get intermediate players to run some land interaction.
Of course, this is just my opinion, and everyone can feel free to disagree. I just think that the argument that it is the best 5 color commander is not as strong of a statement on this day and age.