It makes sense that general purpose instances would have the most users. I’m not a programmer so while I could still register there why would I pick programmer.dev?
The bigger issue I had in picking an instance was just in understanding the differences. I think it would help if instances advertised their stance on defederation, moderation, etc… to help people make a decision (or even to see that lemmy.world may be more similar to some other instances than they might think).
Views that show you multiple communities would be great. Let me see both major Steam Deck communities in one view.