It's really closer to 5%. The super conservative 3% rule (OR LESS) that some people say assumes three things.
- You retire at exactly the wrong time just before a major economic downturn.
- You have no ability to earn money.
- You have no ability to reduce spending.
Literally all three of those have to happen for you to go anywhere near running out of money, and that's not even taking into account that most people slowly spend less and less every year they are retired, cause they either find joy in smaller things, or straight up get too old to do much.