I spent a fair amount of time studying this last year for my spouse & I - we're a bit younger (64 & 66) and have more in traditional IRAs, plus a beneficiary IRA under the new SECURE Act 10 year distribution rule. Picking 2035 as a 'who's ahead' point, a 6-year (until we have to take RMDs) level Roth conversion of roughly 70% of the traditional IRAs was 5.5% worse than leaving it all in traditional IRAs from a total asset perspective. Even out 25 years, the conversion doesn't make sense.
On the other hand doing the conversion basically pre-paid the taxes on a whole lot of money. I chose to put off paying the tax man and didn't do the conversion.
If you go the conversion route, you have to have enough 'outside' income to cover the tax bill.
As other replies have noted, what your estate planning expectations may significantly influence your decision. Non-spouse beneficiaries have to clear out traditional IRAs in 10 years. Roth IRAs can be annuitized for the beneficiary's lifetime otherwise for 5 years (if the beneficiary is a trust, for example).
If you haven't already, I do suggest you open a Roth with a nominal sum to start the 5-year Roth click ticking.
