I started using Twitter mostly to follow journalists and scientists, as you say. There are actually quite a few of them on Mastodon, so it scratches that itch for me. I haven't logged in to Twitter for about a year and a half now. I find Reddit is the harder one to quit, simply because Lemmy hasn't quite reached that critical mass. I still use both every day. I suppose Twitter was also easier to quit because it's mostly Nazis now.