Agreed, I think this is not only for the reason of cheap manufacturing (I doubt it's a lot cheaper than just reusing the iPhone XR case). I think it's just a conscious disincentivisation (word?) from Apple to avoid cannibalising their mainline models :) I'm surprised it's so popular, because I really don't miss the bezel. All-screen phones are a great advancement.

If I had an iPhone I would seriously miss the fingerprint scanner but this is not an issue on Android, the in-screen option works amazingly well.