That is the biggest factor. What many people consider essential really isn't. The latest smartphone. A nicer car than is necessary. A bigger home (rent or own). Entertainment and eating out.
How many people really try to save? I mean REALLY try? Living for the moment and spending everything they've got is much more popular. They will even go into considerable debt just to live more comfortably.
It is a bit of a shame. Just a reasonable amount of regular saving and investing can make a big difference when it comes time for retirement. Especially in the last decade when the stock market has been a bull market. Investors made money.
But saving and investing? Bah! Gotta have that avocado toast.
The avocado toast reference makes me unsure if this is a serious post but I'll respond anyway. Posts like yours have been made throughout this thread and many people have explained the problems with it.
The first problem is that the whole economy is built around people spending their disposable income. If everyone suddenly became super frugal and saving every last penny the economy would take a huge hit.
The other problem is that your argument ignores all the significant factors leading to this problem only to focus on a less important issue to attempt to pin everyone's problems on personal self control. When a problem like this applies to the vast majority of the population that suggests that it's a systemic or social problem rather than an individual one.
Wages are stagnant. You now need to go into more debt via student loans to get those same low wages. The cost of living also continues to rise. This makes it harder for the average person to get by regardless of how well they save.
Sure if every single person became incredibly financially savvy and saved every penny they'd be better off. If you ate only the cheapest possible foods, spent nothing on any for of entertainment or things to enhance or your life and saved/invested every single spare cent you had you'd be better off financially. The reality is though that we're not all perfect and we can't all adhere to strict guidelines like that. Also it's unfair to expect poor people to make all these massive sacrifices just so they don't have to risk going bankrupt due to literally any negative unforeseen event.
Why shouldn't people be able to spend a little bit of their money doing things or buying things that make their life enjoyable? Should that be a privilege that's withheld only for the richest few percent of the population.
I'm not saying that financial education has no place in the solution to this problem. We absolutely should be teaching kids growing up far more about how to handle money and be inancially responsible. Compared to the other issues causing this problem it's simply another drop in the bucket. Also as things continue to get worse and the gap widens further no amount of financial prudence will allow the people at the bottom to avoid living pay check to pay check.