I agree with you here. I used to work in a warehouse, and it was honestly the best job I've ever had. I knew exactly what was expected of me and did the same thing day after day, but I thought it was great. I got all my orders from a machine, I could just listen to podcasts or music all day, and no-one would ever bother me as long as I didn't make a mistake (and even then, nobody cared as long as I cleaned up). When I had two weeks or so left, my boss called me into his office (which he had never done before). I thought I had done something wrong, but it turned out he just wanted to thank me for being a good employee and tell me that I completely surpassed his expectations (which were very low, to be fair), and that I am welcome to come back whenever I want to.A good metaphor would be when I worked on a line in a factory. Most people hated the repetition, but it was great for me. I had a model in my head of the order of things, it felt effortless to keep track of things.
I honestly don't get people who complain about a job being too simple. I'm at a mid-level research job which requires quite a lot of thinking, and though it's interesting at times, and even exciting occasionally, I would still prefer a brainless job which requires no communication. I have purposefully avoided all service jobs to the furthest extent possible, and I'm very thankful to have succeeded thus far. I really feel for people (especially on the spectrum) who can't avoid them.