Meta/FB has pretty decent global search based on names only. Yes, it might take a minute of scrolling and profile pic scanning to find my guy, but it works. Yes, I'm aware that comparing NOSTR and Meta is apples/oranges. I'm using them to illustrate how a good, quasi global search UX should handle these cases.
Discussion
If you had an account named just "Chris" on Facebook it would be basically impossible to find, drowned out amongst tens of thousands of other users, if not hundreds of thousands. I've used that search, it's not that great. My first and last name combination has hundreds of matches, let alone finding an extremely common first name only 🤷♂️
Nip 05 solves this. There are free and paid services, plus it can be set up on your own domain.