For people in a rush they are real food that is hot and ready. Grab it at the store, get a side dish, slice it up, and it’ll feed a family for a meal or more.
I think they’ve caught on because many couples have full time jobs, and want to eat something that isn’t total garbage. They also don’t feel like cooking or the mess.
There may be something to a general malaise driving these chicken behaviors, but we defunded the people that could study that.