Cooking at home means going to the supermarket (or going online and ordering from the SM). If you have to cook for more than yourself, then you probably need to also put sometime into planning the meals for the week. And then of course there's the time to cook the meals. There's also cleanup. Also, let's not forget that there are plenty of people who never really learned to cook and now fear the kitchen.
Sure meals from the frozen section are an option but they're maybe only slightly less expensive than FAFH.
In any case, FAH takes time *and* effort. Perhaps not a lot of time + effort - and habit - but enough to make it easy to say, "F** it. Let's FAFH..."
If FAFH establishments start closing, local towns are going to turn into ghosts towns. FAFH is about the only thing left in a lot of cases; aside from web dispensaries.
People should have been FAH'ing long ago for health reasons and that obviously didn't workout at all.