No, the ideal outcome is not a 50% winrate. The ideal outcome is to enjoy the time I spend playing. That is entirely disconnected from how good or bad I do on a given day.

The way my friend plays Rainbow Six Siege gets him killed every single time without fail. But following "the meta" is really not fun for him. Instead of being able to find a community where we can play with people who might not be as bad at the game as us but are interested in everyone having fun, he gets thrown into the same generic "Casual" pool as everyone else, including kids who play 24/7 and streamers on smurf accounts building a highlight reel. There's no room for playing around, for trying different things, for just playing unoptimally. If you do anything not in "The meta", then you lose, repeatedly, and then the system forces you against literal children to ensure you win often enough to keep that 50% winrate.

Like I said: In the past I could choose when I wanted to have fun, be lighthearted, and screw around by joining more casual servers. Then if I wanted to be competitive, I could join a more serious server, with more strict rules and systems, and play against both people much better than me, and much worse than me at the same time.

Now you have no choice, because everyone is in the same pool, so if you don't play "the meta" or do something nonstandard to have fun, you will be crushed, and then placed against terrible kids, and then placed against really good kids, over and over again. There's no room for casual gameplay because the "casual" section of matchmaking isn't casual.

The most fun we ever had playing Siege was getting a group of 8 people together to play "custom" games. The variability of skill was a huge and important part of the experience. We knew we had to carefully balance the teams for things to not be absurd, and we knew that playing "the meta" wasn't the best strategy in this case because you couldn't assume your teammates to play like perfect robots, giving you the freedom to try different strategies. This is also why people get so damn angry when you don't follow the meta and play like a perfect robot who has memorized all the strats, because if you don't, your team will most certainly lose. You could enjoy games you were bad at in 2001, because game design wasn't so aggressive about "perfect matchmaking" and "perfect competitiveness". I don't want my fun afternoon game to be a damn esport.