Idk, half the apps look like they are just a fork of one app including sync. Why pay for an app that is mostly just a reskin of an open source project.
It just looks like every other lemmy app. They all look the same with a few things changed and their talking points are so similar from app to app. It's almost completely impossible to decifer the differences without trying them out. If it wasn't a fork I wouldn't know because they are so similar on the play store.
If anything, the Lemmy apps would look like Sync, because obviously Sync has existed way longer, even before Lemmy was even a thing. The more likely reason most of them look the same on Android, is because they're following some (sometimes older) form of Material Design, the design standard for Android.
It would be easier just to imagine a generic social media app than to copy sync. It would look similar too because sync is pretty generic in feature set, like all social media apps are in feature set. Besides I pay developers for making a good app not paying the developers to make it a good app.