I agree. I worked McDonald’s whilst I was at college. I learnt a huge amount about dealing with different types of people, both customers and staff!
A lot of people in the UK look down upon people working low tier service roles which I now strongly defend. It also taught me, as it did you, how stupid and ignorant an average person can be and I always try to keep that in mind not just for the actions of others, but my own.
I’m a “skilled” worker now, but should needs must, I’d be absolutely unopposed to going back to a job like McDonald’s.
I used to joke that I’m against national service, but that everyone should be drafted to work two years in the service industry!