Bluesky has brand recognition (founded by the same dude as Twitter), more people and “feels like twitter”, in the sense of what you see, more than mastodon. Also, news outlets seem to be migrating there.
Mastodon (and pleroma, misskey, etc) is seen as a place for weirdos and techies, with “nothing interesting going on”. Several people mentioned this already one way or another, but that most servers/instances are “specific” about whatever means that people will feel that they might miss out on something by choosing the wrong server.
I probably own a significant portion of those games in my GOG account, I’ll double check when I’m home