It's not bad but it's a massive resource hog for what it purports to do. Shame that most of the self host analytics use things like typescript or php rather than more performant languages like Go. Speaking of which:

https://github.com/th0th/poeticmetric

Looks interesting but haven't delved in it too much. I do like how I can create specific analytic tracking events without worrying too much about ad blockers but that's hardly unique to Umami.

There's also another interesting analytics open source project whose name I am forgetting. It was written in C or something and was efficient enough to allow free usage or self hosted, it was a simple hit counter I believe.