High end enterprise products still come with support. That's literally what customers are paying for: a single throat to choke.

Exactly! The "pay a lot of money but get really good support" tier still exists just about everywhere. You just didn't do the first part.

It really depends, support is usually the first thing companies adjust when they want to improve their margins.

Even when you're paying millions to AWS you have to get through their first line of support and they will ask silly questions until you can convince them to escalate.