$10M is never work again money literally anywhere in the world. Don't kid yourself. Buy a $3.5M house outright and then collect $250k per year risk free after taxes. You're doing whatever you want and still saving money.
The problem is if you are the type of person able to get to $10M, you'll probably want more, since the motivation that got you there in the first place will keep you unsatisfied with anything less. You'll constantly crave for more in terms of magnitudes.
NYC and SF both appear to have ~1% property tax rates
Utilities are an order of magnitude less than being taxed ~$35k/yr and hardly worth worrying about while discussing eight figures
Maintenance can vary, but all 3 costs you mentioned combined would be 2 orders of magnitude lower annually than that net worth, which seems easily sustainable?
The neat part is that for a 3.5M house in the Bay area, the only maintenance required is changing the rain fly every year and the ground pad every couple.
And who is going to fix your shower when it leaks, and install solar panels, or redo your kitchen because your parents are living with you now and can't bear to leave their traditional cooking behind?
A whole new shower is less than $200 at REI, and solar generators ship directly to your house.
(And on a serious note - if your parents are both still alive and moving in with you while they have hobbies and self-actualization, you're way ahead of the game)
Assuming they're 40, how far do you think $250k will go 20-30-40 years from now? It's not a stretch to think dollars could be devalued by 90%, possibly even worthless, within 30 years.
I love how the comment I'm responding to literally says "then collect $250k per year risk free after taxes," and then you all pile onto me with downvotes telling me that's he's not just going to invest in treasuries (which is exactly the implication of HIS comment and not mine).
