This is true, but due to the way our taxes work, this nearly always works against Roth's since the contribution/conversion is always at the highest marginal rate in a given year while incomes in retirement always are starting at the lowest marginal rate. The overwhelming majority of folks are better off ignoring Roth's for that reason and the fact that that your highest marginal tax rates in retirement for the overwhelming majority of americans is lower than your peak years. But absolutely should always do the math, but for the very lazy and the very average, you are better off ignoring Roth. Folks who will inherit a fortune or have huge pensions exceptions.
IMO RMD's impacts are also very overrated. Taking out 4-6% is fairly minor to fairly moderate for overwhelming # of folks unless you are pushing mid 7 digit account balance, in which case you are talking top 0.5% account balance for one. Especially as more and more folks retire without high pensions (continues to grow as a % of the pie), Roths value will continue to decline.
it's easy to forget for a lot of people the average median household income is around $75k (Much lower for retirees) with a median federal tax burden is about $1.5k. If you are way over that, especially in retirement, you are not remotely close to average/typical. Advice on these type sites are better suited to "normal" except where the situation is obviously not normal. but just my two cents.