I think if this is implemented, it should be configurable for each community. On [email protected] for example, people posting there will often have just made a Lemmy account so they can ask for help. Not being able to post images would make this harder so they would probably just make a post in the old subreddit.
The things you say you want are the complete opposite of lemmygrad (and hexbear). I’d avoid lemmy.world, apparently the mods there abuse their power, and the fedi is meant to be spread apart, Lemmy.world is getting a bit big. I don’t see why you should go to a Lemmy instance specific to politics, but the only ones I know of don’t follow any of the things you want. I’d say to join a general purpose instance, maybe one in your country? Or you could join a topic specific instance like the programmer one and the various star trek instances.