It also enhances the botrk, but it actually takes out a defensive item or the trinity in the equation. Also sated jax has pretty weak clear, no sustain and low pressure. I don't think he's that good. Yi for instance hits the powerspike sooner, has better synergy with the item and can farm faster. And the ganks, I don't think Jax ganks/counterganks are better than Yi's, especially post 6. Yi can just take TP/smite, powerfarm all day and countergank with TP because since he farmed so much, he's gonna have a level advantage over the opposing jungler and can turn it around.
It's a bit rough to take TP on Jax, you also farm slower ... i'm kinda repeating myself.