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.
Lemmy instances run on servers which are funded by donations. I don’t see how Sync (which is made by one developer) gets to be frowned upon because there’s a price for ad removal. All FOSS projects are somehow funded, usually by donations. Nothing runs for free.
If we get to use all the FOSS Lemmy apps is because someone put in the time and money to make it happen.