57 different 3rd party apps is probably a good start. Mastodon has to be easy to on-board and it isn’t for someone with no technical understanding what domains, servers or instances are. To that group Bluesky makes sense. You are signing up for Bluesky. Try to onboard that group to mastodon and they don’t understand if they are on mastodon.social or mastodon.world or any other instance.

Why would they be on one of those fringe services with less users than bluesky? That’s what a non expert understands