Yes, those facts are individually true, but there are also techniques to turn someone's unarmed attack against them - knives aren't a
disadvantage. I've got a heck of a lot more training unarmed - including, like, half a dozen moves that are specifically knife counters - and if I was stuck in a fight with a knife involved I'd still much rather it was in my hand then in my opponent's. Knives turn what would be glancing blows into nasty cuts, and solid blows into crippling strikes - the mechanical advantage of the blade is significant, even without increased reach. Historically, people wouldn't have used knives over bare hands nearly every time they got the chance if it wasn't an advantage. Ninja superstrength does make unarmed attacks nastier, but they'd also let you do nonsense things like punch a knife through ribs, and without as much risk of hurting your hands with all that force.
I'm not saying knives should automatically beat unarmed, but unarmed beating knives by default, between
equally skilled combatants, feels really weird to me. Unarmed has the advantage of being better for taking people alive (see joint locks, etc), but for killing and maiming knives should have the edge.
Pun not intended
.