The people put on phone support are at the absolute bottom of the hierarchy. They are the least knowledgeable about your problem, and the least empowered to do anything about. Oh, and they also hate you.
Well, kind of. They probably don't hate "you", but they sure as shit hate their job, their managers, the company policies, the guy whose sole purpose is to wag his finger if you log in two seconds late. There is plenty to hate in a call centre, but for the most part the customers are cool enough.
I can confirm that most are totally oblivious to whatever product they're supporting. It's all knowledge bases, wikis and checklists, and man are they ever confusing and poorly curated. Often times agents would be so wound up trying to read all that garbage that they'd completely miss some crucial bit of information shared by the customer, going down some rabbit hole, troubleshooting the wrong issue and getting all tangled up in the process.
During my brief stint at $BIGPCCORP's call centre, out of about 200 agents on our floor, we had three hardware wizards, maybe five coders, and the rest were completely unskilled, except for a week's training on the company's previous gen products. They really hired any warm body willing to work shit hours for shit pay, and that reflected in the performance metrics. Us three hardware wonks jockeyed for the top three spots, followed by most of the coders, and then a huuuuuuge gap in call times for everyone else (I'm talking 30:1 between top and median agents).
So really, for clients calling in, they had a 1.5% chance of getting a rockstar techie, a 2.5% chance for a really decent techie, and a 96% chance of wasting the next two hours of their life over something as simple as a dead hard drive. The irony ? They took the best people off the phones to put us in different, non-customer-facing roles. I left shortly after that move.