My experience with Mastodon is that discovery is terrible. It’s great that it’s open, but it was far too much work to find people and topics to follow outside of my instance (indieweb.social). BlueSky makes discovery natural and easy.
My experience with Mastodon is that discovery is wonderful. It is natural and easy - no algorithm, no manipulation, nothing at all. Just type in details of person you want to follow and follow them.
Their discovery is so bad that they were touting new discovery algorithms for account recommendations in some recent release. So much for "no algorithm".