Interestingly, the longer link is better because it includes a list of relays the event can be found at, which is very important long-term for finding content. Ultimately, I don't know that there's anything we can do about link length that isn't centralizing.
Wish list: coracle direct links work in most contexts, but boy are they long. This is a problem when posting them to, e.g. SMS.
The satellite.earth client has much shorter direct links. I'm guessing they use a hash, or possibly a database with random ids.
An example of a satellite.earth direct link:
https://satellite.earth/thread/note1cy5ggl77z0z5u9tup993wsl9me0tanhsudm9ueefr4glqmwcrresv6exhf
Of course, given the nature of Nostr, I can post with Coracle, and then get a direct link from satellite.earth.
Discussion
Since the url already has a particular host, "all" you need is a shortcut database. There are 3rd party sites that shorten urls as well, but better if the original url site does it. Of course, that means storing more data.
