That’s a fair concern. You can check the data for yourself on the awesome-lemmy-instances repository; alternatively I have made this tool to make the search more interactive and user friendly: defed.xyz.

Short answer to your question is: 410 is a lot. They are the second instance for number of defeds, only beaten by feddit.dk. Most big instances tend to have between 30 and 50 blocks, with the notable exception of sh.itjust.works which has only 5.

To give credit where credit is due, few of the instances blocked by beehaw actually run Lemmy and even fewer are active (2 or more monthly active users). This doesn’t change the fact that it’s a BIG number.

edit: pinging @Cube6392@beehaw.org as this partially answers their question.