Let's take an example. I'm going to use Swedish living conditions and salaries as an example as that's where I live but they are close to most European/western countries. We have a frugal grocery store cashier who makes $2000 USD/month after taxes. We have a high level executive in a medium-sized company who makes $5000 USD/month after taxes.
The grocery worked lives like a student (student loan/benefits in Sweden is about $1000 USD/mo) and saves the rest on the stock market (assuming average yearly yield with reinvested dividends at 8.5%), efficiently saving $1000USD/month for future non linear income. The cashier plans to stop working early at 55, at a net worth of about $2 900 000 USD. This allows for a safe withdrawal rate at about $10 000 USD/month. At this level travling/vacation expenses isn't a problem for the cashier. Housing probably does but they can most likely live comfortably even if they decide to rent. They can also easily increase monthly spending allowance by 10% if they decide to continue working half time.
At the same time our executive have been burning through every pay-check, and have effectively no net worth at the same age, sure there's plenty enough to lease a nice car, don't care about restaurants bills but more expensive traveling will still be a setback and vacation time per year is certainly limited as income is still linear to time spent.
So in this example we have a cashier ending up as a multi millionear set for life at 55 with no need to work a day more and a high level executive who'd be back at 0 without the job and a strictly linear income.
Sure salary increase does matter, but in the long run underspending matters more. With a longterm plan it's possible to become a multi millionaire with an entry level job, for instance there's a famous Swedish railroad worker who recently passed away who ended up with somewhere around $17 000 000 USD net worth at the time of his death, and achieved this by living under his expenses with a low salary and investing the rest, he initially turned to the stock market because he couldn't afford a house in his youth. Not Jay-Z levels for sure but well beyond what most people would consider very wealthy.