Interesting, I tried a few windows that I don't normally "zoom" and you are right. I suppose prior to this I only ever attempted to perform this action on browser/document/messaging/media windows that are able to be fully maximized.
> there's a big, stupid, slow animation that must play every time you switch between workspaces
I wondered how I never noticed this, and it looks like I had Accessibility > Display > Reduce Motion enabled.
> you cannot float windows from other applications over a fullscreen window
Agreed, I found it handy the first time I discovered I could move a floating window over a maximized window in Windows, but I've also noticed that I let my windows become a lot more disorganized when I'm using Windows. I'm not saying they're related, it may be that I just don't have enough Windows experience, but I do find that I end up keeping my workspace a bit tidier on macOS or a tiling WM.