Primal forces you to use it's Cache relay or it don't work, overriding what you want to see from relays. And if you have your own relay,

Most Nostr relays just were designed poorly. ditto is probably the best because it has admin controls and uses Postgresql which can use a memory cache.

Most decentralized tech in this space uses postgresql+Redis to scale to many users.

This is not the case for Nostr.