I haven't heard any advisors stating numbers this high. Please provide source. Plenty of people retire in their early sixties with 1M or less. The amount you need depends on many things
- Where you live (taxes, cost of living, etc)
- What your fixed expenses are
- How much travel you want to do
- Do you need home renovations
- Do you want to buy a car every 4 or 5 years
- Do you need to pay for any college or weddings
- How your money is invested
etc, etc.
Lots of variables. While more is better, most folks will not have 2.5M to retire and will do just fine. Always advisable to meet with a planner to review your numbers and see if you can meet your goals with what you have.