Is there a possibility that it’s an issue with the desktop Firefox? Maybe it’s sending “garbage” to Sync due to profile corruption, etc. The passwords in your desktop Firefox work fine? Maybe try clearing its cache, if you haven’t already, or go nuclear by creating a new profile, then set it up as you want, and adding your passwords, then using that new profile to see if you can sync your passwords, etc. Sorry, but other than that drastic action, I’m out of ideas.
One other thing, do your browser history and bookmarks sync?
Ouch, that’s not good.
Have you tried force stopping and deleting the cache in Firefox for Android? Maybe you might need to clear its data and reinstall Firefox for Android again, which might force Sync to work. It’s possible your profile is corrupted. You might well lose some settings if Sync doesn’t repopulate, but it seems that you’ve already lost stuff due to Sync not working.
My desktop Firefox syncs my passwords to Firefox for Android quite well.
However, yeah, I do think that Firefox’s development over the years has gone a bit awry with the attempt to out-Chrome Chrome. It’s still the best browser out there, though.
Why not try to convince yourself by actually trying it for a week. Do your own hands-on research, as you’ll have a better appreciation of the browser. It’s not as if your device is going to explode if you try something other than Brave.
Welcome to the world of tomorrow!
My manwich!
Wimmy wham wham wozzle!