This is a nonsensical and unrealistic fear/threat to be putting at the top of your list.

The biggest problems are happening right now not in some 90s sci fi films.

One of those threats is automated weaponry and mass surveillance, but not in the comic relief way you speak about it.

In that individuals can be, and that its very difficult to actually do a broad search because content that might exist in one might not exist in another, and that the types of people to run them often dont want search engines indexing them

Also, I don’t see locking data from search engines as a bad thing. The fediverse isn’t search engine searchable either

The fediverse not being searchable is one of the biggest flaws with it, and make it similarly ephemeral to Discord, except its actually worse because the sizes of communities are just in that goldilocks area of awfulness where there are echo chambers, and people are rude and toxic. Whatsmore, availability due to the small size is relatively mediocre.