You've clearly never had to deal with a company in a monopolized industry like telecommunications. The call center needs to be there on paper, otherwise it will give people the option to cancel their contracts or even initiate lawsuits because something doesn't work and the company is unreachable.
The call center doesn't need to provide quality support however; as long as it is there on paper it is all that matters. In reality the call center is costing the company money and they'd rather not have you on the phone as long as you keep paying your bill (and most people will keep paying even if they receive subpar or lack of service because of the lack of consumer protection laws in the US, forced arbitration, the fear of a hit on their credit report or the lack of competition).
The people in this thread are acting like call centers are all bad when the real problem is the monopolized industry and not the customer service agent.
Also in more benevolent companies, providing support over the phone is the most expensive way to provide support. So as much of that that can be shifted to automated systems, better products, etc the better because it avoids the high cost of a call center.
While a call center employee may be paid by minutes on the line (though I think that is rare), they would be penalized for taking too long on a single call or helping too few customers. There's little incentive to spend time on longer more difficult calls when you could just focus your effort on solving many of the simple calls instead.
It's not just in monopolised industries, but the entire process has been labelled "low skill work" and left to fester.