When I picked up YNAB, I was already making 90k or so. At the end of every month it was tough to make rent, and we would live on rice and beans for a week. We lived in fear of the day that a larger or annual bill would show up. Health insurance? Panic. Tax bill? Drink and panic. Emergency needing some real cash on hand? Don't even think about it.
A budget lets you save in advance for those sudden shock bills. Now I don't even notice when the insurance bill comes due; I've been gradually putting aside money for it all year. What's more, we can afford way more important stuff. We were able to self fund two successful companies, we take extravagant vacations, and our quality of life is much better, just because we now set money aside in advance. And fwiw, those two companies more than doubled our income.
It's important to work on increasing your income through an improved skill set,better jobs, etc. But you can reap multiples of every dollar, and even new income sources, just by taking control of your expenses.