All you need to know is no taxes
People hate taxes, but they don't love the Roth IRA.
If you hate paying taxes then you'll love the Roth IRA.
A Roth IRA allows you to contribute money for retirement and withdraw money tax free during retirement. If that appeals to you then that's all that matters.
Let's look at that again with some numbers. If you put $100,000 into a Roth and it grows to $1,000,000 after which the entire $1,000,000 is tax free once you reach retirement. The alternative is to put $100,000 into a 401k and it grows to $1,000,000 and then you owe taxes on the entire $1,000,000 once you reach retirement.
Don't complicate the Roth IRA by comparing it to a Traditional IRA or trying to figure out which tax bracket you'll be in once you retire.
What does it matter? It doesn't.
"All you need to know is no taxes."
Well that and if you still qualify.