Here is the answer https://www.theidioms.com/the-devil-is-beating-his-wife/

Sync for Reddit has always worked without Play Services if you patched out the ads with Revanced Manager ;) Why the developer included a crash instead of an error message is still a mystery to me. We can’t be the first to point it out, can we? Let’s hope there will be a Revanced Patch for Sync for Lemmy.