Yes - that’s basically the only thing I can come up with too. But still not everyone will be invited or be willing to pay so it seems incomplete.
nostr:note1pydljw887ntqt6emxkhweazpsnlfqsjkkezcjuddq9y4dmyp5rjqt5agws
Maybe we can have newbie discovery relays that use Cloudflare turnstile or something. Iris.to uses it for nip05 name registration. At least it's a temporary fix.