Shameless self promotion of the page I just published earlier today including this information (along with other stuff). Though to be clear, this page is for Lemmy/Kbin/Tildes. Not the greater Fediverse.

https://github.com/Zak8022/Awesome-Rexxit-Resources

IMO, this would solve the problem, while keeping the benefits of being decentralized. I could go to my “Community Group” called “Tech”, I could see all the aggregated results of Beehaw’s, kbin’s, etc, tech Communities.