VC funding enables the high salaries in tech. You can definitely be bootstrapped and work 4 days a week, you'll just have a hard time earning your current salary.
VC funding enables the high salaries in startups
and that is because those startups are competing for talent against high margin, highly profitable other companies which can afford to pay very well.
Those startups are competing with other startups and ultimately VC money.
There's significantly more tech talent out there than the business problems that can be solved profitably with said talent.
When the VC money runs out and the "growth & engagement" engineering playgrounds close up shop we're going to see a massive readjustment. We're in the beginning of it now.