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.
I was thinking about it, but I'm not sure Jgrim would like to completely remove all news and political communities.
The issue here is that this instance would have to accept to not federate those communities, which can definitely be an issue for a generalist instance.