I migrated away from Evernote a few years ago, where I kept my "paperless life" (PDFs of receipts, bills, etc) and general notes (work, study, etc). Opting to self-host most of the things I can, I moved the notes to Dokuwiki and the rest to what is now Paperless-ngx.

This year I realised that Obsidian suits my needs better than a wiki, so migrated the notes to that. If it's just for your stuff, I'd recommend the same. (Though if you collaborate with anyone, I've heard Notion is a better option specifically for that.) Obsidian has a lot of extensibility, which will steepen the learning curve, but it's worth it.

I sync Obsidian's Vault using my Synology NAS's "Drive" client, and Obsidian works perfectly with Windows, Mac, Linux, and Android. The only shortcoming is iOS (because iOS), though I believe you can work around it using Obsidian Sync or at least one other tool I've seen mentioned. It might also be possible via the Obsidian Git extension, but I've not tried it with iOS and requires (from a self-hosting perspective) that you have a local Git server (for example).