I think it comes down to escapism. People read to escape their normal, perceived boring lives. On the page are people like them, living in an extraordinary circumstance.
Something that's always bothered me about the writing community is this advice of putting your character through the absolute wringer. Anything bad? Throw it at them. Throw everything and the kitchen sink at them and watch as they struggle to get out of it. Just when they manage to crawl out from under it, throw more shit at them! Make their lives a living hell! RAWR RAWR To the point of ludicrousness.
...and maybe many readers don't really want that. They don't want to read and escape into somone's life which is one huge shit pile that never seems to get any better except for maybe at the end, if they're lucky, and the suffering actually has a huge payout.
The struggles that many characters labor under are those struggles we see in every day life and for that brief moment, the reader finally gets to escape into that magical world where it's surmountable and their life becomes easier to manage.
I know for myself I really, really hate reading about
crapsack worlds (warning: TVTropes link). Some readers love them and that's great. But not everyone does and I think this trend of wish-fulfillment bears some of that out.