It's very possible that the hardware performance is hiding the issue. I upgraded from my 2020 intel 13" mbp (16gb of ram, 4-core i5) to 16" M4 Pro for a variety of reasons, but the basic processes of MacOS were making it nearly inoperable periodically throughout the day. I gifted the old one to my gf, and I can hear the fans spin up from across the apartment when nothing else is happening but indexing. I recall regularly being irritated that I'd just have to wait a while for the indexing process to finish before getting anything done. Idk wth is going on, but it puts far more strain on the system than anything else I could throw at it except games and Docker. Even ProTools doesn't seem to produce audible noise unless a bad plugin or a rendering is taking place.

Aside from that, the Settings menu memory leak (or whatever it the problem is) is very much more apparent on the older mac than it is on the new one, but it's still reproducible. Neither computer is running Tahoe yet, these issues were already present, but based on on your comment, they might now be functionally worse in addition to being a performance and user experience joke.

My new Mac is still amazing hardware-wise, and since those issues seem to just be compensated for, perhaps by having efficiency cores that they're able to delegate background processes to, but the sluggishness and in-adequacy of frontline processes and apps must be embarrassing for what I presume to be smarter engineers than myself who probably just don't get to allocate time or energy toward any of the problems, especially with things like Xcode and SwiftUI also having major issues, and the mac being a relatively small market.

I make a habit of turning off spotlight almost entirely. Search never returns what I want anyway, and the juice isn’t worth the squeeze.

Go into preferences, spotlight and you can add folders to exclude from indexing. I add my home directory and most of the system directories and that more or less fixes the issue.