I used to work tech support. Those lines are there because they work. In only 9 months, I had a few different people tell me they were pc repair techs and knew what they were doing, and I didn't need to do the basics.

I did them anyhow because the company said so, and I found that more often than not, it fixed the problem.

If I had sent that to second-level support without making sure of it, I'd have been written up.

So yes, they're trained to treat callers like they don't know what they're doing, because they often don't. Even if they claim to.

The best thing you can do is just go along with it quickly and get it over with, even if you've already done it. There's no way around it.