3 ideas
Every dollar in a traditional IRA or 401(k) is partly owned by the IRS, because the tax was deferred rather than forgiven, and the unpaid tax grows along with the balance. The account statement overstates what the owner has, and the gap widens as the account compounds and future tax rates stay unknown. The planning question is therefore not how large the account is, but when and at what rate that embedded debt gets settled.
The SECURE Act replaced lifetime 'stretch' distributions for most non-spouse beneficiaries with a rule requiring inherited accounts to be emptied within ten years. That forces large withdrawals into the beneficiary's peak earning years, pushing income into higher brackets and turning a gradual tax drip into a concentrated tax hit. The practical effect is that the government collects the deferred tax sooner and at higher rates, so planning has to happen during the original owner's lifetime.
Because tax rates can rise and forced inherited withdrawals push income into higher brackets, the owner should move money out of pre-tax accounts while their own bracket is low. They can do this through partial Roth conversions that fill the current bracket each year, or by withdrawing funds to buy life insurance that passes to heirs tax-free. Paying a known tax today at a chosen rate replaces an unknown and likely larger tax later on the heirs.