What rubs me the wrong way is the $20 ask to remove ads

I would feel the same way if Sync was the one and only option to view Lemmy on mobile but it’s not. You can use all the other FOSS apps which don’t have ads.

By the way you can install a global adblocker on your phone to remove all (well, most let’s say) ads across your device. I use one and don’t see any ads on Sync, just a blank square.