My experience with customer support with every major company has always been a miserable one. The fundamental problem from my perspective is that if I've decided to call support that means I've already exhausted any other alternatives, and most likely my issue is one that explicitly requires human intervention because I've found myself wedged into a crack in the self-serve systems. I'm not particularly bothered by waiting 15 minutes, but what pisses me off the most is that when I finally do get a person they're also not empowered to do anything except read to me from a script that is word-for-word identical to the documentation on the website which was written by Legal instead of someone technically competent.
What I really want is something like https://xkcd.com/806/ to be a real thing. In a fit of irony, the one time I got somewhere useful was when I called Comcast/Xfinity. I was able to isolate a problem with my connection to an aggregation router in their network that was not very far away from me, and I happened to know was in the middle of a major public construction zone. I actually managed to get someone on the line finally who could direct information to their network engineering team and it was discovered that there was a partial fiber cut caused by the construction and it was repaired a few hours later. It's hard for me say anything positive about Comcast, but I was pleasantly surprised that day that I was able to get information to someone who could do something with it, even though it was not exactly the smoothest process.
Most companies you just run into a competence wall. Generally speaking, I am not calling because I don't know what to do or don't understand something (unless its a lack of understanding in the sense that the company's process is utterly stupid and therefore incomprehensible). I'm calling because I fully understand what needs to happen, I've thoroughly investigated my issue and identified an appropriate outcome, and I have a good understanding of the systems involved. I simply lack the necessary access to make it happen and resolve my issue, so the customer support line is simply a gatekeeper. In the infinite cost-cutting wisdom of miserable bean counters everywhere, customer support has been so disempowered in most cases that they are then gatekept from actually doing anything also, and are often bottom-dollar workers in cheaper third-world countries, so also lack the competence, context, and care to actually effect any positive outcome even if they have the access.
Realistically, customer support systems are not customer support systems, they are legal compliance systems that are designed to find the cheapest and most defensible way to tell your customers to fuck off after you already have their money.