Compared to the amount required to not want to spend most of their time grinding to acquire a decent life.

We're missing any kind of definition for "a decent life" (or indeed "grinding" for that matter).

I live in an region where the population density is at least 50 times less than that of greater London. We have few Michelin-starred restaurants, a distinct lack of opera houses, and no top-ranked universities. I'm not bothered in the slightest.

Living in London (or NYC, or the Bay Area) is, just like so many other things in life, a choice.

To the amount of wealth they are generating for the place they work perhaps?

the USA there is a reason FANG companies like London