Imo all apps like facebook, twitter, Instagram, reddit, imdb, or anything else that requires network and gives almost no benefits are pointless (and always were).
I'm not gonna lie, this was like one of two sentences I understood lol
Speaking from someone who's worked on both, there absolutely is a case for native Android apps. The biggest is engagement, having push notifications is huge for getting people to come back to your platform. Quite frankly, once Lemmy apps start getting going with notifications, there will probably be a really nice uplift.
Secondly, you can currently do way more with code running on the device than Javascript in a browser. Video editing comes to top of mind.
theoretically app requires less bandwidth for requesting only JSON
This was the other half sentence I understood, and I think it's wrong. Most apps are SPAs with cache, so for a lot of cases the only thing going through the network is JSON.