The scaling issue is:

- We are being told to limit ourselves to 3 relays.

- We are also being told that the Nostr network is going to be broken up into millions of relays, each hosting distinct and separate "communities".

Put the above two points together, and it's not hard to see, Nostr will never give you access to the worldwide stream of chatter like Twitter did.

It doestn't scale up to any experience that remotely resembles that.