Welcome back,
You'll see the same communities/magazine no matter what's the instance you use. However, some delay due to federation is possible, it's espacially a problem with .world due to their relative weight.
The local feed means you'll see post from your instance, which may-be interesting as you'll see content you like if you choose a thematic instance, but it's not a blocking feature.
Then there is a bunch of weird instance, like grad where right-winger are role-playing being leftist by shit-posting on how much they love Kim il sun or Vladimir Putin. these are defederated by most big instances and you won't see their content (and believe me, you miss nothing)
My hot take is that we get full automated commercial plane before single pilot.
Single pilot means that there is no way to avoid an air Berlin like mass murder (and being locked alone in a cockpit doesn't sounds great for mental health). No pilot means less risk to have such a scenario
Sure we need risk analysis (accident caused by humans versus humans preventing accident) and most likely newer ATC protocols, and some upgrade in equipments, but I doubt there it a major obstacle.