I, too, don’t love the use of AWS/Cloudflare, while I get that you can simply replace AWS S3 with something else for backups, this server setup is innately based on using Cloudflare.

Logseq, it’s a lot like Obsidian as it also has knowledge graphs, tags, is markdown-based and self-hostable but, in contrast to Obsidian, it’s fully open source

Macs/MacOS has enough problems, no reason to make anything up

I would recommend to switch as well, PopOS isn’t that actively developed at the team, because the team is currently developing its own desktop environment which isn’t out yet. Linux Mint is great for new users (especially from Windows) and supports all major desktop environments. If you don’t have anything against using the command line from time to time, both Debian and Fedora are great options, Debian isn’t corporate-run but Fedora gets faster updates.