As a pro bono thing, for the past 2+ years I've been working with a guy that has been in prison for 28 years. They have TV and stuff, they aren't in a time capsule. They have a convenience store too, it's called a commissary. I haven't seen it, I imagine it's like a 7-11 but 3 times as expensive.
And no, if someone has been in for decades, they don't go back because it's "simpler." If they got 20+ years, then they've just spent a lot of that time being model inmates so they can get the **** out. The LAST thing they want is to go back. If they go back it's because they can't make ends meet on the outside (because prison did not prepare them for employment and because of societal views of felons) and have to do something to survive.