My point on ROTHs was that someone had proposed taxing them like regular IRAs... sure, not likely but ...
I am pointing this out that trying to make decisions of what MIGHT happen to taxes going forward is a fools game...
Your point is that some wacky change could come our way (i.e. Roth gets taxed like traditional IRAs) that none of us would have foreseen / planned for. So it is a fools game to make predictions / decisions about these unknowns.
But some things are easier to plan on than others.
I don't think tax rate changes fall into the wacky bucket. Rates have changed multiple times in my lifetime. It would actually be quite shocking if they stayed the same for the next 30 years.
There are also just 3 possibilities on what future rates might do:
1. Go down.
2. Stay the same.
3. Go up.
Regarding #1, rates are already historically low and we continue to have big deficits each year. I think #1 is very unlikely. And, if rates were to go down, it would most likely be minimal. Like the 22% bracket goes to 20%.
I think #2 or #3 is much more likely.
Regarding #3, I would not be surprised to see the 22% bracket go to 25%, and then later on to 28% - or something similar to that. As recently as the year 2000, income over ~44K was taxed at 28%.
So, I don't think it is a fools game to make some educated guesses about future rates and take actions accordingly. For example, with whether or not to do some Roth conversions.