Well, when TF2 came out, it was laser focused. Every class had a role, and was strong and weak against certain other classes. So now, you throw a bunch of new items, and it loses that. The sniper is weak to spies, that's how it's supposed to be. So then the sniper gets given a shield that makes spies unable to stab him, and a jar that he can throw on the ground and reveal them. Engineers were weak to snipers, but now they can take control of their sentries and manually shoot things outside of the normal range. So the end result is that everything ends up becoming pretty okay against everything. I haven't played the game for a long time so I don't remember everything.
The other issue, which is one of the reasons I stopped playing (aside from me pretty much stopping playing video games in general) is aesthetic overload. I don't like the notion of things being called "purely cosmetic" because appearances have meanings. The 9 classes were designed to be recognizable from their silhouettes alone, which is pretty brilliant. But now you can pile an absurd number of things onto your character, completely changing that. Not only do you not know what your opponent is equipped with anymore, you also have an additional psychological blocker to identifying them. And it's just tacky. TF2 was originally a 60s spy movie parody, and I really felt that. Now it's just... everything. It's just a lot less compelling to me.
Well, when TF2 came out, it was laser focused. [...] The 9 classes were designed to be recognizable from their silhouettes alone, which is pretty brilliant.
That's interesting and quite disappointing to hear. In Valve's in-game commentary, they specifically point out that they were trying hard to achieve exactly this (distinctive outlines). It sounds like there's been a complete change for the vision of the game, likely due to personnel changes.
As someone who has played 1000+ hours of TF2, I do agree that this is dissapointing. Some items have changed silhouettes, and that can hurt gameplay.
However, TF2 was very much on the right track to have the perfect combination of revenue generating side-items with unchanging gameplay. Just because they've strayed a bit does not mean that it can't be effectively used for other games.