I think the main problem with searching for fediverse posts is not that they’re not indexed but the lack of a singular tag to append when you want to search for them. To search for reddit posts it was easy because you could put in your keywords and stick ‘reddit’ or ‘site:reddit.com’ onto the end, but now there’s too many domains to keep track of and you can’t rely on appending ‘lemmy’ pointing a search engine towards all Lemmy instances, let alone kbin/mbin instances.
It’s the first floor above the ground level (or the first floor that you have to start calling a separate name, because if everything is single level you don’t need to specify a floor).