Earlier quoted context omitted.
Yes, I have 'reduce transparency' set to true. Overnight after upgrade the UI became noticably sluggish. The outstanding example is Spotlight. For years since the M1 release I have been able to bring the bar up and type C-H-R then Enter, in ~500ms I guess, and I would always get Chrome. Now, I have to wait another 1-2 seconds for it to think. If I hit enter before it has finished thinking, Spotlight goes away and not…
Fair enough. With Tahoe's removal of Launchpad, I assume you're talking about Spotlight in the sense of what appears when you press the Launchpad icon (F4)? Anyway, I can confirm that I also get very weird laggy behaviour from it—sometimes a double-press is interpreted as two presses, sometimes as just one.
What's even worse is I have disabled all search categories for Spotlight except Apps and System Settings. It's searching a list of 40 apps and idk maybe 200 settings, and it still sucks.