The two main problems most folks miss when they compare pre-tax 401k to Roths is
1) You have to add in the value from your tax savings in pre-tax 401k in a taxable account to the value of your 401k. Me putting in $19,500 into a pre-tax 401k allows me to save $8,190 in taxes, which I can and will use to invest elsewhere. So I have to compare the value of both the 401k ($19.5k) + investments in a taxable account ($8.2k) in 25-45 years after taxes to the Roth in the same time period. You can't ignore the value of the tax savings up front and only compare on the back end.
2) Roths can and likely will be changed in the future - look at the current proposals. It's very likely Roth accounts over just a couple million will have taxes at some point IMO. Just like SS was not taxed for a long time but now 85% of it is taxed for anyone with other assets. I'd much rather have the guaranteed tax savings today than the hope that it'll be tax free in 25-45 years.
The only people I think roth's really make sense for are very young folks not making any money that have family that will contribute to Roth OR folks who are going to inherit a ton of money OR will make a fortune with company they started or startup that made it huge.
#1. Yes, I understand this but this exercise is to equalize "tax rates" across working year vs pre-SS years vs RMD years.
#2. Yes, and that why the goal is to equalize "balances" across all 3 buckets: Pretax, Roth and post-tax.