It's all related. Emulation, compatibility and compatibility-through-emulation are very old and well-studied topics. The reason why it's not present on Android is because Google doesn't want to, not because they can't.
>The reason why it's not present on Android is because Google doesn't want to, not because they can't.
Sad as it may be, I imagine that lack of desire also comes from consumer demand. Most people don't care about running those 15 year old games, so what's the motivation?
For archival's sake, you should be able to seek old APKs and run older ROMS through an android emulator. So the minority of those who care have options.