The real threat is what happened to search.

Some services will give you custom algos for discovery. If clients don't let you choose, algos and clients may merge and we're right back to twitter, running their own servers, blacklisting free speech servers from their ultra popular client.

We will only have Free NOSTR if either

1) it's not that popular; or

2) we continue to run free servers in the dace of popular services.

The masses will never be free because they just want to be.