The link to https://browse.feddit.de/ is dead and should be updated to https://lemmyverse.net/communities.
Personally i think it would even make sense to link this from the main site sidebar. Not because it is a problem finding communities on other instances from within world, at least this should be the best instance to be able to, but as a function of being a “role model” for other instances.
I was lamenting that instances don’t link to community browsers / crawlers.
The link you sent has a link to this post, https://jlai.lu/post/541698, which has links in the Guides (en Anglais) section to external sites, world’s getting started guide and some other, both linking to the dead browse.feddit.de link. Really hard to find, got to be really dedicated i guess :) And now the link is even dead, haha.