I used i3wm for 5 years. I still miss it after switching to the new MBP 3 months ago. Using mouse to manage spaces is so tedious and wastes 2-3 seconds each time, which added up quickly throughout the day.
I was also a die hard i3wm fan who started using MacOS on a new job.
I am currently a (mostly) happy user of Yabai. There's some blog posts from folks who made the same transition, lemme know if end up taking a look and still have questions, and I'll try to answer them.
Try BetterTouchTool or Magnet. Magnet's UI is a little nicer, but that doesn't really matter since you'll never see after you've set it up. I prefer BetterTouchTool because the shortcut keys are more flexible. Perhaps you can match the i3wm keys to leverage that existing muscle memory.
I am currently a (mostly) happy user of Yabai. There's some blog posts from folks who made the same transition, lemme know if end up taking a look and still have questions, and I'll try to answer them.