2.5m at 3% SWR (https://www.investopedia.com/terms/s/safe-withdrawal-rate-swr-method.asp https://www.investopedia.com/terms/s/safe-withdrawal-rate-sw...) would

2.5m at 3% SWR (https://www.investopedia.com/terms/s/safe-withdrawal-rate-swr-method.asp https://www.investopedia.com/terms/s/safe-withdrawal-rate-sw...) would generate 75k per year thus resulting in a negative burn rate and last for infinite time (or at least until society no longer uses financial instruments). At the very least, it'd last much longer than "several" decades.