What's happens if, like mastodon and matrix, 99% of ppl only use the handful of the biggest Lemmy servers?

let's address the possibility that like mastodon/matrix 99% of ppl will flock to the biggest handful of servers

What is the real value of decentralization given that? Outside of like political unrest.

And what role do small servers really do in that landscape? Obv "novelty" servers like midov cater to the like lolicon enthusiasts and I'm sure there are a few other servers dedicated to illegal things. Regional severs are quite compatible with various nationalists/patriots