Slightly less cynical take: I'm always a bit skeptical of how these studies define "paycheck to paycheck". I remember there was one that defined it as "do you have enough money in your checking account to cover the cost of $BAD_THING?" And one of the top responses was "no, I'd need to pull from my savings account". IMO the distinction between checking and savings is kinda arbitrary. I move all of my cash (beyond what I need for monthly expenses) into a savings account so I can get an extra $100/yr in interest. That certainly doesn't mean I'm living paycheck to paycheck.
It looks like this study broke the paycheck to paycheck group into those that are struggling with their bills and those that aren't. When you look at the breakdown it seems like all of the growth is in the group that is paycheck to paycheck but not struggling with their bills. I'm not sure how to interpret that.
Loads of people I know spend their entire pay because they don't save. Like, saving just isn't a thing for them. They're not in poverty, they're not rich, they just don't save, they don't care.
They also don't maximize income either. They do whatever job sort of works and enjoy their life.
Trying to build a retirement whilst earning $20K a year is like trying to become a bodybuilder whilst eating only donuts. You can't just be all like freewheeling and shit, you need to play life like it's a game with win conditions.
But yeah, you can just not play. Most people don't, they focus on other things that give their lives meaning.