I have to say, as something if a social media virgin, I am puzzled by #4. I have never been a Facebook, Instagram or Twitter user. Previous to getting into the Fediverse, the only platform I engaged with that could be considered social media was Reddit, and I left that behind because of the whole brewhaha over third-party clients.
Since finding my way here, I have become an enthusiastic user of Mastodon, Pixelfed and Lemmy. I could not have imagined that it would be easier to acclimate myself and i have not encountered any barriers to entry, or at least I have not recognized any.