You are overvaluing the Power/Vitality benefits and under valuing the cumulative productive benefits of the other attributes. At Mythic, the highest power/vitality boost is +5, so even with 700 Citadel levels (the amount necessary to achieve 100% bonus and ignoring all other choices), your additional benefit is another +5 points. Let’s say that all epic attributes followed your theory of “best” option or the way “the system was designed”, you would pick up an extra 120 Power and 120 Vitality (treating them as equally divided amongst the 12 gear pieces similar to the forced Rare attributes). 120 Power is good, that translates to 240 spell/chip dmg. If you replace just one of those with a Strike trait that is aligned, that’s a 5% boost to your dmg, which could be as much as 400-1200 dmg. If you replace one of the Vitality with a Ward or something like Solid, or even Cover, you are getting 5% mitigation vs incoming strikes as high as 25k; that’s as much as 1.2kdmg mitigated, a lot better than 120 Vitality. The accumulated benefits of all of the collective attributes, all except speed expressed in percentages, give you exponential benefit compared to Power/Vitality.
Also given that several skills have a base value of 0%, like Block or Crit Chance, etc., your primary way of boosting these critical stats is through attributes. They already forced the lowest value attributes on us as Rare attributes. Every additional Strong/Life attribute is a wasted chance at an exponentially greater or more rewarding (Rich/Smart) benefit.
EDIT: went back and rechecked my stats and my math is not good up here. ignore this and read further down is my advice 