If they live beyond their means that means they cannot afford to be a millionaire, and can't ***** about it.
You can have the new car, the expensive house, and all the trimmings or you can dial that back a notch -- still have your needs met, and save the money. But, even if you could just do 10% or 5% that would take you off this "paycheck to paycheck" scenario. Can you live for a year without pay? You should be able to, something could happen where you couldn't work that long...
If you ask these people how much they save, they'll tell you "save what", but if you ask them about how many times they go out to eat or go to the movies it's every week. Guess what, that's where the "savings" went.
If you ask me about those questions, it's never and never. I rather keep the money than waste it on something that lasts about five minutes or is just marked up to hell and back. Catch the movie on Netflix or even rent it on Amazon -- still cheaper than the theater and your whole family can watch it for the price of one ticket. If they're poorer ask them how much is going on weed and going to the club, lol. You will find that's where a significant amount of the wasted money goes.
If the people make more money they tend to spend it on travel, they'll still have an empty bank account -- effectively having no more wealth than the supposedly poor person. If you spend it all, you have no wealth... How much you make is irrelevant, it's how much you keep.