So in the home game I've been running for going on a year now, one of my players is a self-described powergamer. A few months ago he confessed, with tongue partially but not entirely in cheek, that in most games before this one he felt his biggest accomplishment would be if he could make the DM cry - i.e., come up with some loopholing combo of powers that could exploit RAW to effectively work as a cheat code and do an end-run around the carefully crafted obstacles of the scenario.
I am perfectly okay with the idea that 5e does not especially support this style of play. It doesn't need to be a tent that friggin' big.
In our game, this guy is a delight to play with - he's proactive, he does things that forward the plot, he often makes choices that are interesting instead of "optimal." His style balances well with a group that has varying levels of time and experience in the hobby and want diverse things out of the game. I think I can take some credit for this, because I invest a lot of time and care in the game, I'm not an adversarial DM, and I want everyone to have the kind of fun they're looking for as best as I can provide it - he wants to kick a lot of ass, and I'm happy to give him lots of opportunities to use his powers to be awesome doing it. But the system helps, simply by not being fiddly in ways that make it easy or tempting to rules-lawyer. It's set up to be a conversation between the players and the DM, and that suits our collective style well, even though it means having to find the sweet spot among a number of different player goals.
(Which, by the by, is why, having seen this diversity in action, I cast a very serious side-eye on assertions that "everyone power-games" and "everyone optimizes." Yes, if you dim the lights and squint, you can sort of say that those words include most of the things players do, but whether it's intended to or not, saying these things feels like a gotcha-game rhetorical flourish, an attempt to say, "Actually, you agree with me, if you'd only admit it." Which is kinda not cool on its face, really, but also not helpful in that it doesn't actually illuminate the things that are being discussed - so you can dilute the meaning of optimize so that it covers the whole universe of player choices, but doing so sheds no light on what we actually point to when we talk about "optimization" or "power-gaming," which really truly are definitely not things everyone does. Anyway.)
So this probably isn't much consolation to folks for whom previous editions with more robust build choices hit their fun buttons more thoroughly than this one, even if your definition of "powergamer" isn't "rules-lawyer who enjoys playing trump cards at the DM." It's true! 5e probably doesn't support your playstyle as well as it does others. Sorry. So it goes.
The question, then - which the OP can feel is directed specifically at him if he likes, or not - is what does that mean for you? What do you want out of this thread? Is this a problem you want to find some solution for? If so, you're going to have to give in on one side or the other of this, I hate to say. Either accept that you are not the audience for this edition and don't play it, or find a way to have fun playing in a way that isn't your preferred style. Your tastes and druthers aren't going to change, probably - which is fine! Your playing style is a perfectly legit approach to this hobby! - but neither is 5e. Alternatively, do you just want a place to bitch about the disparity here? Also cool, bitch away. Only maybe be clear that what you want is a space to say, "Goldurnit, this sure dissatisfies me," so your fellow posters will quit trying to look at it as a problem to solve. Because, fifty pages into this discussion, there's been an awful lot of heat, but precious little light, and maybe it would help to define just what it is you're looking for here.