The math part is easy.
I'm fairly sure that when I'm 24 I'll be just as leery of banks as I am right now. Assuming banks will do their part for the next 42 years? Nah! So much can go wrong in 4 decades.
Banks are a waste of time - - go with an IRA with Vanguard... One advantage is you subtract what you ‘save’ with Vanguard from your income... (You don’t pay taxes on the money you contribute)/ Another advantage is they have one of the lowest expense ratios in the industry.
https://personal.vanguard.com/open-account/oax/app/psptlanding#/