I can tell you personally that I worked as a tech in a school system for 2.5 years (I also have a bachelor’s degree for computers), this story dates back about 11 years now, way to make me feel old lol. But I found out I was losing my job in the school system at the time due to state budget cuts at the time. I was essentially a field tech because we were a department of 4 people that had to care for 8 buildings. So I decided at the time to apply for geek squad just to see if I could even get part time work. I think I intimidated the supervisor because he was slightly younger than I was at the time.
I later ended up doing tech support (not through them), and would end up fixing some systems where people had taken systems there that they couldn’t fix. I’ve heard stories as well. But they are a big company so there are probably a lot of techs who are highly professional and know what they are doing and probably some who have no business near a computer.