When Microwaves first came out they were huge but with a tiny cooking area and they were not affordable, and were mostly in business kitchens and a few restaurants. I would love a freeze dryer but the cheapest I have seen is $1600 and they only have 4 small trays.
I imagine it depends on the type of food, as there’s probably some proteins you can freeze-dry that don’t have to be rehydrated to eat.