I suppose that’s fair.

Most of the time, one can find an alternative via lemmyverse.net, which runs a spider and builds a searchable list of all communities on all instances.

https://lemmyverse.net/communities

A Threadiverse-wide community search isn’t not something that lemmy makes available, and it’s not immediately obvious to new users.

Sometimes, the community name is different – I was in a discussion the other day where two people were talking about an alternative for “crows”, and I pointed out that there’s [email protected]. And I mentioned that there’s no direct “mechanicalkeyboards” equivalent, but that [email protected] does have some overlap. A lot of times, though, there are communities with the same name on different instances, like [email protected], [email protected], or [email protected], and so a search on lemmyverse.net will turn them up.