I think a lot of it is driven by dysfunction and legacy at Apple. Their whole mindset is they want to review every version of the app manually and every bit of code that executes must be signed. They don't allow a lot of obvious software engineering approaches as a consequence, like partially downloading the app and streaming the rest on demand even though it's an obvious thing to do for mobile apps.
Note how in this story the Android and iOS teams started a big rewrite at the same time, but the story consists exclusively of fuckups on the Apple size. Apple impose an arbitrary cellular download limit. Apple designed a language that can't handle more than 9 dynamic libraries before it hits scaling issues. Apple prevent you from using interpreters or other techniques to change the app after it's installed, unless you use a WebView in which case it's OK for mysterious reasons. Apple don't help even when major brands are weeks away from wrecking their business by hitting these limits. Apple Apple Apple. Meanwhile the Android guys are sitting pretty with Java and now a migration to Kotlin, which is (a) a much better language than Swift and (b) is dogfooded at large scale on the IntelliJ project so you know it scales (had no scaling problems with Kotlin and I've been using it for the last five years).
Note how in this story the Android and iOS teams started a big rewrite at the same time, but the story consists exclusively of fuckups on the Apple size. Apple impose an arbitrary cellular download limit. Apple designed a language that can't handle more than 9 dynamic libraries before it hits scaling issues. Apple prevent you from using interpreters or other techniques to change the app after it's installed, unless you use a WebView in which case it's OK for mysterious reasons. Apple don't help even when major brands are weeks away from wrecking their business by hitting these limits. Apple Apple Apple. Meanwhile the Android guys are sitting pretty with Java and now a migration to Kotlin, which is (a) a much better language than Swift and (b) is dogfooded at large scale on the IntelliJ project so you know it scales (had no scaling problems with Kotlin and I've been using it for the last five years).