High income during working years does not automatically translate into replaceable income in retirement.
Affluent households often save a great deal and still face a shortfall, because the lifestyle being replaced is expensive and the savings are concentrated in taxable-on-withdrawal accounts.
The gap is rarely visible in the balance. It shows up when the balance is converted into after-tax spendable income.
Closing it usually means changing the mix of account types well before retirement, not increasing the savings rate in the final years.