Imagine a relay like a library and an event like a book. When you want to find a book from the library, you can do one of two things:

1. You can put a hold on the book in the library system. The librarians will find the book for you and have it delivered to your local branch, where you can pick it up as soon as it is available.

2. You can go find the book yourself. If it's not at your local branch, you can go to another branch and look for it there. It may take longer to find the book, but perhaps you'll stumble across something else you wouldn't have encountered otherwise.

So far, most Nostr clients can only place holds. You'll get the books you're looking for from your favorite authors, but what you won't get is the opportunity for serendipity among the shelves. There's room, I think, for clients that take you to different libraries and help you explore.