[nrr]

I usually get away just fine with Control+Command+f to fullscreen the window, and Control+Up will open up Mission Control so that I can get two fullscreened windows side-by-side. It's all built into macOS.

Windows 11 adds snap layouts, for which there is currently no analog, but this will let you do the side-by-side thing from earlier versions of Windows as long as you can tolerate the fullscreened windows becoming their own Space. (I actually find this preferable myself, but YMMV.)

[deprecative]

The insistence that window be the only thing I need to be looking at on MacOS is also a frustrating one. No, Steve, I really do want to manage my windows.