Yep. If they do anything besides grumble, this is how my DM tries to fix it. The power to reign it in is just a Thanos Snap away, but they don't -probably out of fear that we will leave the table (and new players are difficult to come by in our backwater area these days). My current plucked-from-the-internet optimization is more of a means to nudge them out of 5e: I'm so bored with the way my table plays it: DM is so annoyed by the power level of Tier 2 and above on even regular joe characters that we rarely touch it and then it all resets. I've never seen level 8 in 5e. Even though many would say that's a problem with the DM, something out of my control, I favor viewing it as my own problem that I have options on how to deal with it. Up to now, I have been ok just rolling with it and playing Tier 1 games bi-weekly for the past 6 years. I've burned out at this point.
I've never had the opportunity to play Champions or Mutant's & Masterminds (since my group = 5e drones), but compared to OSR, 5e feels like a superhero game to me. Is it common for players in superhero games for players to bemoan the Hulk-ish bruiser builds damage output on mooks or feats of strength when their concept was a phase-shifting scout, mentalist, or jack-of-all-trades-master-of-none gadget type? Turning that concept on its head: if the mechanics of the game are a bit loose & imperfect and resulted in the speedster player exploiting rules that put them above the brawlers in DPS, crimping their very concept and deflating their enjoyment, what is preventing the GM from using their Infinity Adjudication Gauntlet to correct the issue? As has already been stated: Personal issues.
It's been pointed out that besides a dozen or fewer of the worst examples optimization isn't something that should be causing an issue unless you have a sensitive table. The PC's are fighting the monsters - PVE, not PVP. Regardless the designers fully expect
you to police any corner-case issues at your table -Rule 0: The Nuclear Option- which you have not stated whether or not you have used beyond talking to them, which is not equivalent to applying Rule 0. Don't want to firmly kill the handful of breaking builds and give them the choice to comply or leave? It's Sophie's Choice to be sure: put off the table or your 2 other friends. Unless you want to go to the other side of the table and encourage role-playing it away in their mind or similar, and you have given up reasoning with the other pair,
you're stuck with that choice. Your power-gaming
* friends have given you an unspoken ultimatum. Getting out of this pickle will require more than complaining about optimization.
No character build is beyond Rule 0 -and no player is
forced to play at your table, but if they don't respect Rule 0, they have
no place there anyway. Aspiring DMs that eschew invoking Rule 0 have
still adjudicated on any matter that puts its use into question.
*non-judgemental