DND_Reborn
The High Aldwin
Yet it had the opposite effect IME.No, it didn't. 5e's progression was specifically tailored to extend what are seen as the "fun levels" while making the other levels go by quicker. It may not be to your liking, but it's a reasonable design.
Requiring more XP at those "fun levels" delays the gratification many players feel when they actually get to, you know, level.
The side effect is that slog in those "fun levels" turns off a lot of groups and by the time they finally get through those levels, they've had enough and begin a new game with 1st level (or whatever) characters again.
As to the OP, there is way too much stuff for me to even consider listing it all...