Income and wealth aren't the same thing. Plenty of households earning £100k+ live paycheck to paycheck because lifestyle inflation absorbed the income. The wealthy households are usually the ones who didn't let spending grow with earnings.
How lifestyle inflation works
Each pay rise quietly absorbs into upgraded car, larger mortgage, more expensive holidays, more restaurants, more subscriptions. By 12 months after the raise, monthly burn matches new income. The raise produced no net wealth increase.
How real wealth builders behave
Capture pay rises into savings before they're spent. Live below means consistently. Avoid status spending (cars, watches, dining) that doesn't compound. Invest the difference. Most '£10 million net worth' households earned less than the £150k-earning household next door but kept more of it.
Building wealth is mostly about gap between income and lifestyle, not income alone. Most people who feel 'stretched' would benefit more from spending less than from earning more.