If this is the way that the fediverse is supposed to work then it does matter which instance you make your account in, which is exactly the opposite of what was advertised about the fediverse. because there may be a niche community which I can't find through the kbin search but that exists on some lemmy or any other software instance on the fediverse.
Why isn't the searching for communities easier? Even on more established lemmy instances like beehaw they don't show communities from non-lemmy instances. Is there some major roadblock or just that nobody has developed a comprehensive search function yet?