That's such a weird little bug, though I get the conceptual overlap with the 'Applications' view; maybe someone just crashed out trying to fit those two together and they shipped a thought-in-progress.
It's still stuck in Beta 3. But after BetterDisplay has been launched the standard brightness slider is also usable again. I think it has to be moved in BetterDisplay to let it jump to the right position.
Since I updated twice I got this "" Error message "" and from what I saw is something that happens to several users. I'm at 26.0.1 I hope 26.1 It will have it fixed. I never had it happened to me before.
Error Msg:
"Your system has run out of application memory" .. NEVER had this happen in Sequoia!