I've been a web developer for about 25 years. I can assure you if something doesn't work the users usually
won't raise a ticket. They'll work around the problem. On the occasions when they do raise a ticket it'll usually contain minimal information. Having a telemetry system to correlate it against gives you some information to use to debug the problem. That's helpful.
Understanding that users have more important things to do than spend time on bug reports is an important lesson to learn. If you can gather data without relying on someone whose job is to worry about other things then you will make everyone's life easier.