I think this is really the issue, there are a lot of relays online but usage is concentrated around a few big ones. Most newcomers to Nostr probably just stick with the default relays that their chosen client is set up with and never really consider what relays to use.
And that is fine, there are many clients and more will spawn with time. That’s exactly how Nostr was envisioned, fragmented AF 🐶🐾🫡
It works and we’ve seen big relays go away or get nuked without any major issues but I think it could still make sense to have more quality relays and have notes a bit more distributed across them than we have now.