The site: https://lemmyverse.net/communities
To see kbin “magazines” (that’s how subreddits/communities are called on kbin) you have to switch to displaying them in top right corner:
Or you can just open this link: https://lemmyverse.net/kbin/magazines?order=followers
And to go back to displaying lemmy communities you have to press on “communities” in the middle on the top of the site:
https://www.quippd.com/writing/2023/06/15/unofficial-subreddit-migration-list-lemmy-kbin-etc.html
https://redditmigration.com/
https://sub.rehab/ (I requested them to add my singularity sub but they didn’t add it so there’s for sure many other alternative subs that are not on the list but are active)