All I can say is: Literally decades of video game design have consistently shown you are, in every way, wrong on this.
I am not talking about video games and what works well in Video games does not necessarily translate to what works better in D&D.
Also, people routinely make choices that make their video game play more difficult. For example, you can play Baldur's Gate 3 on Story Mode or you can play it on honour mode or anything in between. From an "optimization" standpoint story mode is better than honour mode. You literally can't be killed. your character in Baldurs gate is FAR more powerful in relative terms when played on an easy difficulty. Yet I think very few people "optimize" in this fashion.
TTRPG design isn't that different.
It is way different IMO. Further even if it isn't different, it is contrary to your central argument. BG3 is the most popular fantasy D&D game of recent era (perhaps ever) and there is very little balance in it. BG3 is far less balanced than 5E and far more popular, and it is a safe bet the people buying and playing BG3 over and over again are enjoying it.
If video games == TTRPGs, then Baldur's Gate 3 proves that you are incorrect on your observation that balance improves the game play experience.
The consistent complaints about 3e and 5e have both been exactly the thing you claim people won't complain about: that some things are overpowered compared to others, and shouldn't be
. Consider the hue and cry about silvery barbs, or the Twilight Cleric, or even going all the way back to the original UA Storm Sorcerer, and how people said (essentially) "this is getting bonus spells that the other sorcerers don't have", so WotC...chose to cut out the Storm bonus spells, rather than issuing errata for the PHB. (One of many decisions that eventually contributed to 5.5e.)
Not really, I've seen that on message boards, but not in game.
The only complaint I have seen about Silvery Barbs (and Absorb Elements) in play is that a DM banned them. It is actually the opposite of what you claim - I have seen people complain specifically about the efforts made to balance the game and to the point that the entire rest of the group of players asked him to reverse his decision.
I played multiple campaigns with another player and as a DM with a player playing a Twilight Cleric and never heard a single complaint about it, nor have I observed anything at all negative from it. Ironically, despite the hand wringing on the message boards over Twilight Sanctuary, one of the four PCs I have had killed outright in a game was in a game with a Twilight Cleric, while Twilight Sanctuary was active.
I don't play UA so I can't comment on the Sorcerer.
Players can take care of story themselves. They're really quite good at it, in fact. They don't need to be shepherded into a realm of storybuilding
Exactly! Which is what quotas on encounters do. Shepherd the players into those encounters.
The proof is in how people--consistently, here on ENWorld, on Reddit, in WotC surveys, in wider gaming discussion--have responded to 5.0 as it developed, and how 5.5e was tested, and what 5.5e has become since releaseily based on
5.5 Design was heavily based on surveys, so I think the opposite is actually true. Surveys and playtests got us what we got in 5.5. Supposedly 5.0 was based on that as well.
Further time and time again it was the surveys that prevented WOTC from taking bolder steps and got them to undo the bigger changes they had in the UA. Many of these changes that were in the UA and then cut specifically made the game more balanced and they were rejected.
I do agree there are many people on message that complain about these things, but I have no way of knowing whether they are a majority or a minority, and I also see plenty of people complaining about the large number of fans that won't let WOTC make big changes.