I get that until recently it was considered normal and relatively cheap, but you are literally paying someone else to make food for you.
It can’t be sustainable without exploitation of workers and/or animal welfare to have that available to the majority of people on a regular basis.
If you can only afford fast food as a luxury, to me that seems like a good thing.
A friend of mine switched from a dumb phone to a smart phone some time in around 2015. He said that the dumb phone was keeping him isolated from the rest of the world. He was unable to communicate with the with certain people because they were sending messages using whatsapp, facebook and all that modern spyware trash. It was too late to stick to a dumb phone back then, and now it’s even worse. If you want to isolate yourself from the people around you, a dumb phone has become an excellent tool to achieve that.