My first full time job was in a fast food type place that was privately owned. It was called Biscuit Time. I was 13. The manager there was the best manager ever (in fact at other FF places her name was tossed around as someone to recruit, she was well known as being the best manager). That place was clean. The food was well kept (prior to cooking) and fresh. Food was never served old or cold. People lined up around the building for their food and were very pleasant even if there was a long wait. The food was that good. I thought that was how it would be at any place. I was wrong.
I have worked at Hardee's once for 3 weeks, a BK, McDonald's twice, a sit down restaurant in the mountains of NC, many years in the pizza business, and some time in a doughnut factory. Of all of those, the only place that was actually somewhat clean and fresh food was pizza.
None of the FF places adhered to time limits on cooked food. The last time I worked at McD, the manager himself served fries that were an hour old. I had asked him twice in that hour if I should dump and cook new. He said no. The customer returned with the disgusting cold fries and when he found out the kid was the manager, he freaked out. As would I. I quit shortly after that. I had no job prospects, but could not work for someone that cared so little about the food (a description that fits most FF mangers)
The sit down place was run by two men that had no idea what they were doing. I poured some iced tea and saw things swimming in it. There were animals of some sort that bred in it, they looked like mosquito larvae but that wasn't what they were. It was from pouring the hot, new tea into the existing tea I think. Very nasty. They also didn't know they were supposed to wash the pans they cooked the pasta in. They just kept rinsing them at night.
In the pizza place, there is little room for food problems. The oven is so hot, it takes care of anything, but the product prior to going in is benign also, due to the preservatives and the high turnover of pizza toppings. The only one I ever questioned (and so, tested with my thermometer) was the Italian sausage and at times the regular sausage in the heat of the summer. The cold line had a hard time keeping up when the temp outside was 100. When the pie come out of the oven, the same cutter is used on every pizza. If you have a decent staff and manager, it is replaced with a new cutter at least once an hour. You can also request your pizza be cut with a clean cutter if you order vegi pizza, pizza no cheese, pizza no sauce, or have issue with beef or pork. With any of these things, the workers should have no problem changing cutters.
The doughnut place I worked in was the same way, the way they were prepared would've killed anything. But it was the only facility I ever worked in where I came upon a bucket of writhing maggots in a storage room. I was so freaked out, I just walked out. I was a boss, so I did send someone to clean it up, but I do not know what caused it. I was not a food boss, I was a delivery boss, so my domain was the dock, not the production line.
My 1st hubby worked in an Applebee's for a few weeks. Disgusting things happened regularly according to him. Like a steak being dropped on the floor, then thrown back into the pan of marinade.
I will not eat out. My reasons are more about the ingredients (I believe deeply in organic), not the prep. However, the likelihood that there is a pathogen in your food along with the GMO, sad cow milk or meat and ammonia is 90%. There is a bistro here at our local organic store and they do have dishes that are GFCFSF. I could have a bite there. You can see the whole cook area. But I just make all the food at home myself. It is cheaper and safer.
eta: in McD one time a kitchen worker spit on a burger when he was pissy about a customer. I reported him and then had to quit because of the backlash (first time I worked at a McD) from everyone.