How To Read The Break-Even
Cashback is already in dollars. Miles are not, so the comparison rests on one number: what a mile is worth to you. The break-even is the value per mile at which both cards come out the same for your spending, after annual and conversion fees.
If the trips you actually take give each mile more value than the break-even, the miles card comes out ahead. If they give less, or you are not sure you will redeem at all, cashback does. A premium-cabin redemption can look very valuable on paper, but count that value only if you would have paid for that seat in cash.
Caps matter more than headline rates. A high cashback rate with a low monthly cap can pay less than a plain lower rate, which the "effective cashback rate" row shows. None of this holds if you carry a balance: interest will outweigh any reward.