In order to avoid this, what would you think of having a "new joiners" instance, where
hexbear, lemmygrad and ml would be defederated
politics and news communities would be blocked at the instance level
That could help to onboard people, so that the first time they look around, they see more gardening, cute comics and casual conversation rather than another set of depressing memes.
Disclaimer: politics and societal issues are important and should be discussed extensively (they are quite popular on Lemmy, let's be honest). I'm not advocating to hide them all, just to not show them as the first content people potentially interested in Lemmy would see.
That's kinda what Bluesky has with their "moderation lists" or whatever it's called. They have an entire dedicated MAGA one that blocks all MAGA accounts that join Bluesky automatically for whoever is subscribed to it
I don't know enough about this, but couldn't a script be made that imports the starter pack for people? Instead of just politics, you can really customise them to fit a certain theme to help with the onboarding.