Why shouldn't I put 100% equities in my Roth? And only place bonds in my Trad?

Ignoring 401k and HSA, let's say I have a Trad IRA and Roth IRA for retirement.

Let's also say I want an overall 80/20 portfolio.

Given that I have to pay taxes on the gains in the Trad shouldn't I limit my growth assets there and keep most of my growth in my Roth?

So my Roth might be 100/0 whiley Trad is like 70/30. Wouldn't this be better for end ofife tax issues?