That works for very niche streamers/creators. Maybe with an older audience as well. If your a streamer on twitch or YouTube chances are your audience isn‘t older than 30. I personally don‘t really use email for actual communication. Twitter is pretty much perfect to communicate to an audience. Yes it isn‘t federated but at least you‘re using a bunch of different platforms to diversify risk.

Generally I would advise new content creators to be present on every possible platform.