Then you leech off kin if you have any? We invented old people long before we discovered pensions and tax-advantaged retirement savings accounts.

The range of plausible return rates is hilariously wide, so nearly any withdrawal scheme that can provide a reasonable baseline standard of living with a low chance of going bust is extremely likely to grow faster than you spend it down and leave you with large amounts of money left over. Portfolio survival rate is a very artificial metric that does not accord with how people actually concretely plan their retirements outside a particular band of upper-middles who are weirdly allergic to the fact that they have social ties (and rich enough to avoid them).