It’s really not that hard to do. People do sometimes overestimate how hard it is to do basic legal tasks.
Filing a simple John Doe summons in your home jurisdiction and then sending a subpoena to YouTube for the offending contact information is pretty trivial. You could probably find someone to do it for you for a thousand bucks or less.
Admittedly that’s not free but in a context like this with real money at stake it’s not a huge obstacle.