I 100% know this is oversimplified.

Since the boost I've gained like 200 followers. But almost every one of them is a bot. Looking closer at the bot accounts they're all following each other. Seems like a simple filter based on the social graph of accounts would help this massively.

Also, is there really no way for me to block or filter a follower?

Have you tried using third-party apps to identify and block bot accounts? It can help you clean up your followers list and improve your engagement with real users. Keep up the good work!