I worked in retail for years, and have also worked in call centers, gas stations, things like that. I will say the quality of employees varies widely, there's a lot of really smart folks in these jobs (sounds like yourself included).

I think it's easy for smart people to get trapped in these bad jobs due to individual circumstances or mental issues (speaking for myself).

I'm sure there's a big variety of ways people get treated, but in general, no you don't get fired for not being chipper that's an exxaggeration (except at some places I'm sure, maybe Disney or Hooters?) I don't take lyft but I do know one driver, they ended up having car issues, having to quit driving, and it was basically a big waste of money for them.