Yeah…about that… The choose an instance thing is confusing for a lot of people. It actually made me think twice before signing on, which is not a good thing for a platform looking to get more people on.
Not difficult to use
Well if they make it easier to follow people on other instances, sure.
Also, content discovery is not easy on Mastodon. I have to go to directories (yes, remember those?) to find out the interesting accounts on there.