Endurance will take time to be filled to maximum.
Stamina takes too much time to be filled to maximum.
Strength takes too much time to be filled in any capacity.
Either Strength needs to be able to be filled in other ways than just punching entities, or its gain rate needs to be bumped considerably - since if my research is correct, Strength gain rate is one tenth of Stamina's, which itself has one tenth of Endurance's gain rate.
Running to build up Endurance and Stamina is perfectly feasible (one more than the other, though only because of percentiles), but how often do you actually find yourself punching (or swinging melee weapons) at stuff? It's pretty hard to do that consistently unless you're confident the admins won't swat you for trying to farm attributes. Having the gain rate of 0.001 does little to help with that.
Also it's basically impossible for vorts to build up Strength since we have fickle empowered melee that does not contribute to the attribute gain, but trying to smack entities with fist SWEP would look weird and 99% of people would ask "uhh, why are you punching that Zombie without using vortessence? and why are you doing no damage? aren't you vorts supposed to be really strong?" but maybe that's just me being pessimistic.