The base config is full of sensible defaults and the learning curve for shortcuts was relatively short for me. I use it alone as my WM with picom as compositor (which is unnecessary) and no DE. I've never looked back and whilst there are some alternatives in win/OSX, I miss it so much when I have to use a Mac or boot into Windows... having to constantly move, resize and fiddle with app windows is such a pain I'm glad I don't have to worry about with i3.
Bonus tip: I recently switched from i3status to i3status-rs[1] which provides an excellent status bar for i3 (developed with Rust, which I hear is apparently a major selling point for many). I'd strongly recommend this.
Linux is my daily desktop+laptop driver for work and personal life, and i3 is the main reason for this. To me, DEs are full of bloat. I would stress, though, that it's not for everyone at all.
[0]: https://i3wm.org/