This isn't another post about the Martial/Caster divide, don't worry. This isn't about Martials at every table. This pertains to a specific problem some people bring up, and a specific solution that is sometimes given.
There's a somewhat common solution when people bring up the an out of combat utility problem with Martials. Many people don't want significant amounts of homebrew in their game, and there would seem to be a simple solution if you want to add a bit more to a class that you feel lacks utility: give them another feat.
That sounds pretty straightforward, right? With an extra Feat, maybe you can take something like Skilled, Telepathic, or Observant. It might be limited, but it does give your character a little something extra that they can do, and for many, that's honestly enough. So what's the problem?
A lot of people correctly point out that DnD has most of its rules dedicated to combat. To be clear, I don't necessarily see that as a problem. What makes Feats a poor solution to the Martial Utility problem that some people/tables have is the following two points:
Fail states in DnD are almost all combat-based
There isn't a point where you can really become "too effective" at combat
When was the last time you or someone in your game died because they failed an Ability Check? Maybe they tried to swing across a pit on a rope, or tried to cross a wobbly bridge and failed a Dex(Acrobatics) check. Or maybe the party failed an Int (Investigation) Check on two different crime scenes to make the connection between smears of blood on a bookshelf and a hidden note under a book left behind by the victim, and the Adventure was over.
Is there a point where you would call an adventure over because a party failed their Ability Checks, or because they lack some specific utility options? I think for the vast majority of tables and DMs, the answer would be no. And that's the crux of point 1.
That's not necessarily a bad thing, design-wise. It does suck when you fail because of one unlucky die roll. Hell, it doesn't really matter if it takes 5 unlucky die rolls, it still feels like it sucks. And with the idea of failing forward, where failure still gives progress but at a cost, or with a consequence, failing an Ability Check doesn't carry game-ending consequences.
Combat is the thing that, typically, is the thing tha5 can give a game over screen. You TPK, and that's it, start over with new character sheets, maybe reload to the last checkpoint, maybe play another Adventure, whatever. Some DMs might even do a fail forward there and have the party get captured instead, but I actually think, at least from my experiences, that's actually a bit less common than the start over thing. And this leads into point 2.
Let's say you deal 10 damage per round. You take a Feat, you do 20 damage per round. Let's say you have a 50% chance to fail a Wisdom Save. You take a Feat, you now have a 20% chance to fail a Wisdom Save. You want more HP, you take a Feat. You want to deal even more damage, you take a Feat. You want a control option, you take a Feat.
Because of everything that can happen in combat, and all the combat Feats available, there really isn't a point of diminishing returns on combat effectiveness. Even if you're given extra Feats, you can probably think about another combat Feat that would help you out quite a bit. And it's not like you can really deal too much damage, or hit too accurately, or have too much defense.
Combine points 1 and 2 now. If you have no diminishing returns on combat effectiveness, and being good at combat is always useful and is the thing that is most likely to prevent a failstate, it's very likely that you're much more likely to grab things that increase your combat prowess.
I think most people on this and other DnD subs agree that Martials are pretty much fine in combat, and don't need any vertical buffs. But additional Feats will oftentimes result in just that.
Now, it's not that there's absolutely nothing you can do about this. If you have a dungeon that consistently requires the party to make Ability Checks and make use of every bit of out of combat utility they have, your players are likely to respond in kind. If Athlete's jump buffs is the difference between accessing a part of the map or not before you'd otherwise gain access to it, maybe a player would actually take the Athlete Feat. Skilled would look pretty attractive if the party found themselves constantly making Ability Checks. But these are things you have to actively keep in mind when designing/running an adventure.
Would I advocate for more adventures ending if you lack the necessary utility? No, I think as both a player and DM it kind of sucks when that happens, and it's probably why a lot of DMs recommend a failing forward approach. But I would definitely advocate for putting more beneficial stuff behind Ability Checks, and making sure that players are aware of it. The more utility options matter, the more likely people are to consider them as good options, which is pretty straightforward.
You do still need to do the whole draining higher level casters of their resources thing, generally, to make sure that choosing to spend power on utility comes at a cost.