This doesn't feel terribly surprising to me. MacOS has always had impressively performant parts, but their upgrades always generally lower responsiveness. On modern hardware it's less perceptible obviously, and they want to sell machines, not software. But the last iteration that felt like it prioritized performance and snappiness was Snow Leopard, now twenty years ago.
I will say the problem was a lot worse before the core explosion. It was easy for a single process to bring the entire system to a drag. These days the computer is a lot better at adapting to variable loads.
I love my macs, and I'm about 10x as productive as on a windows machine after decades of daily usage (and probably a good 2x compared to linux). Performance, however, is not a good reason to use macos—it's the fact that the keybindings make sense and are coherent across an entire OS. You can use readline (emacs) bindings in any text field across the OS. And generally speaking, problems have a single solution that's relatively easy to google for. Bad-behaved apps aside (looking at you zoom and adobe) administering a mac is straightforward to reason about, and for the most part it's easy to ignore the app store, download apps, and run them by double clicking.
I love linux, but I will absolutely pay to not have to deal with X11 or Wayland for my day-to-day work. I also expect my employer to pay for this or manage my machine for me. I tried linux full-time for a year on a thinkpad and never want to go back. The only time that worked for me was working at google when someone else broadly managed my OS. macs the only unix I've ever used that felt designed around making my life easier and allowing me to focus on the work I want to do. Linux has made great strides in the last two decades but the two major changes, systemd and wayland, both indicate that the community is solving different problems than will get me to use it as a desktop. Which is fine; I prefer the mac-style to the ibm pc-style they're successfully replacing. Like KDE is very nice and usable, but it models the computer and documents and apps in a completely different way than I am used to or want to use.