OP literally has "fuck you" money.
If I had that kind of balance and just decided to start residency because whatever, I am almost 100% certain I would end up putting my mouth where my money is.
Mu dad is a wealthy doctor and I can live off inherited money if I desire. I am still pursuing medical schools and neurosurgery. Prestige and status matter, too.
PGY-4 here.
If you love neurosurgery, stick with it. Not for a year. The whole thing.
If someone wrote me a check for $11M, I'd like to think I wouldn't quit (If I wasn't in prison for refusing to pay the taxes or something). I'd probably have a nicer place, maybe a Tesla, more help etc... But if you leave, you can't buy your way back into all the crazy shit we get to do. I think a lot of us would agree "I hate being a neurosurgery resident it's awesome."
If you'd rather become a VC or Angel investor or consultant or drink on a beach, you probably don't LOVE neurosurgery. It's OK to like it and not love it. It's even OK to love it and leave it because it will never love you back (neurosurgery does not love you back, it's an abusive relationship).
Maybe take a long look in the mirror and ask yourself if you're relieved you don't *have* to do this job or if you're pumped about how less worried you are about the hardship that accompanies *getting* to do this job.
You've got a good problem. Make a good decision. Congrats either way.