So literally 2 cities. Wildly expensive cities like DC, Seattle, Boston are still highly livable on $1.5 million.
Honestly, if you're regretting your life choices so severely but you're unwilling to live anywhere but NYC/SF, you're either not really regretting your life choices that much, or you're just really bad at making good decisions with your life.
I'm making the assumption that there are more jobs that pay $500k+ in Silicon Valley and NYC. If you can get that salary in 2nd cities like SEA or BOS then of course you're doing better than someone making the same in higher CoL places.
Honestly, if you're regretting your life choices so severely but you're unwilling to live anywhere but NYC/SF, you're either not really regretting your life choices that much, or you're just really bad at making good decisions with your life.