Random technical details: You can take money out of a 401k in a couple of ways that aren't retirement. The best way is an authorized reason: Up to a fairly small amount towards a first home. If you become disabled. If you are a victim of certain crimes. If you have a small (< $1000) emergency you cannot cover[0]. You can also take out that money at any time, paying a penalty on top of the tax required.

There is also a way to borrow money short term from your 401k that turns into an unauthorized withdraw if you don't pay it back in a relatively short time (a year?)

These all seem reasonable.

[0] Yes, there are rules to prevent the worst abuse, mostly limiting you to doing so once every three years, the small total, and the need to fill out paperwork explaining the unexpected cost.

The problem with “paycheck to paycheck” is that it evokes images of people struggling to make ends meet—to pay the rent, keep the lights on, and put food on the table. But a lot of people today are using it to mean someone who’s living beyond their means—spending $1100/month on a brand new pickup truck while sending their kids to private school and maxing out their 401k. That’s not a problem of an unfair economy; it’s simply poor discipline. And so when a half-assed marketing survey asks people if they’re living paycheck to paycheck, you end up with 60% of respondents saying, “Yes,” when in reality only maybe 20% are struggling because they’re in a truly difficult situation. The rest of them may just need to settle for a less expensive car and maybe turn down their 401k contribution for six months so they can pay off their credit cards.