I'd be scared to "retire" even at 65 if I only had $2m USD, but it's one of those things where you just have to take that risk. Or keep working.
The biggest mistake that some retirees make these days is liquidating their 401ks or re-configuring it to mostly cash and bonds.
Huge mistake. Inflation would insure their wealth would be cut in half within 10-15 years.
The risk has now completely flipped 180, it is far less risky to keep your retirement wealth in equities and other investments after retirement than to go to cash/bonds.