"you can carry it out 10 or 20 or 30 years and the math works the same."

If, for every conversion, you pay the taxes from the distribution, and if you also incur an early withdrawal penalty for using the funds to pay taxes, you would be falling behind and you need a new advisor.

Think about the cycle of events, for two scenarios. Give them both the same age and amount in Traditional IRA, same investment mix and income tax bracket. One converts a fraction (say, 15%) every year between, oh, 40 and 55 and pays taxes from available funds. The other does no conversions. Now project out 20 more years, for growth. Who is better off at 75? Because the time value means the majority of any fund is (hopefully) growth/income, not your own contributed funds. That's why a younger person would want to put into Roth early and why, if you can afford the tax on conversions with outside funds, there is only upside to conversions as early as possible.

Obviously, all of this is simplistic math, not actual computations to meet someone's specific needs.

You would not bother to convert and pay taxes when you are near or at the stage of taking RMD and going to be reporting that for income tax anyway; unless you can afford that tax hit because of having both activities (conversion and RMD) and you still want to shelter some of the funds by moving them to a Roth.

For instance, doing conversions at 70 might make sense for one person and not another, depending on their overall financial picture, life expectancy, types of investments, needs in their old age. My father-in-law lived to 94; did we anticipate that? Yes, actually. It runs in the family.

Dave Ramsey holds his bankruptcy against himself. I don't see how that is an issue. As for advertising, how is that different than getting content any time you watch television, listen to podcasts, radio, audio books, other programming and even most printed materials, because, although I skip forward on lots of video, all that branding is everywhere. Look at the amount of product placement in video productions; every time you see a logo, an Apple iphone, a Ford truck or police car, etc, that got paid for. It doesn't result in you patronizing all of the advertisers on those shows, I assume. Heck, we still don't even have a Panera, although we got promise one a few years ago.

"The fee is not a percentage of the account value?"

Fee agreements vary and are not required. That's what "self-directed" means = no broker manager, no management fee. Besides, your example investor still has the funds in Roth, converted from Traditional. That doesn't shelter the Roth from fees, if there is a fee agreement in place. Oh, your comment is directed towards the person who didn't make a full conversion and paid the taxes out of the conversion as a distribution? Again, that's not the best strategy for conversions.

Investment planning and management includes a lot of opinions, many of which you can get from sales people, of course. Annuities, whole life, bonds, and other strategies will certainly make some investors feel more confident, and makes the other people more commissions.