Aranging windows is not a "power user feature". It's a basic thing that all other desktop OSes have. If you think hotkeys are "power user" things then replace them with gestures. Mac has none.
They actually do have windows splits, it's just unfortunate that they force a workspace onto them.
If anything workspace is a power user feature. Many including myself rarely use it. I could not if I wanted to because it looks so stupid on an ultrawide monitor.
To me the fact that 2 basic things: window snap and window switch hot keys (dont tell me you can switch apps, then swicth windows, it's retarded), don't exist, and I need at least 2 other apps to make my computer bearable, is ridiculous.
It's luckly that the apps happen to be free no thanks to Apple.
You’re mad that Apple didn’t design their operating system around your personal preferences. Personally, I’m accustomed to the way the Apple does things and personally feel the Windows way of doing do things very annoying to use (I end up needing to use Windows a few times per week). So I guess we cancel each other out :) Linux desktops have every feature under the sun but they have so many other problems I find them utterly unusable. That is why I use Mac, perhaps you would be better suited with a different platform if it annoys you so much. Sounds like you just prefer the Windows workflow ergonomic to me.
Also, FYI, you can split left and right on mac by hovering over full-screen button while holding the option key: https://imgur.com/a/VNSQR8l
I'm using Hammerspoon to implement manual tiling and pretend to have old Spaces (spaces arranged in a grid with instant transitions), but it's not my favorite thing ever.
But they can support like two features for every single power user: hotkeys for managing windows and snapping to windows when you push it against the border.
but...why? just install Rectangle and forget about it why does it matter so much if it's "built-in" or not..? It's like complaining that Apple doesn't make Alfred built in because you don't like Spotlight.