Are touch screen car stereos good or do a lot of them end up not working after a while compared to traditional stereos?

They are tested before they shipped.  You can assume that they have the same reliability as regular stereos.  Innovate or stagnate.

Last year, I almost rear ended an 18 wheeler by being distracted to the stock touch screen HU. I was driving my friend's car. It was the 2019 hellcat charger. I was speeding at nearly 100 mph. If you crash into a semi truck over 30 mph, you are dead. Every driver NEEDS to keep their eyes on the road.

My cars don't have touch screens and I like them fine. I rented a car with a touch screen  once and it was so distracting while driving, I couldn't operate it- the damned seat heater was on and it was a hot day. I parked and corrected it. I don't know if they malfunction, but they do work through the car's computer (OEM touch screens), so there's another layer of control to work with. They can be as durable as the rest of the car, depending on who engineered it. I would not swap out the stereo i have for a touch screen. I go home when I want to watch a damned screen.

I have never had a problem with one.