Before echolocation was discovered, Lazzaro Spallanzani ran several experiments on bats to figure out how they could fly so well in the dark. Including making little bat blindfolds. After they were still able to fly just fine, he gouged their eyes out with a needle.
He concluded that bats don't need to see to navigate.
The fediverse isn't one singular entity. It's a bunch of individual independently managed instances that link with each other (or don't, if they so choose) via a shared protocol. Think of it like email.