150HP was tried in the beta and flopped terribly, it was tested and did not work, even with multiple damage buffs like 35 damage on shurikens, bleed on dash, 8 second blade etc.
And he most certainly isn’t a low effort hero.
Nanoblade hardly ever cleans house, much less than 90% for sure, you’re completely overstating it’s power.
He is also a mobility-oriented hero, hence why he has a lot of mobility, who knew that a mobility based hero needs a lot of mobility to be viable?
He’s balanced, and certainly Jeff disagrees with you. You are completely overstating his power and kit, not even OWL Genjis can consistently pull off the shuriken combo you listed. He’s balanced, get over it.