(Bokken is based on the katana because it's a solid hardwood katana.)
Oh believe you me, I know how strong hardwood can be, you can actually bust bricks with a thick handle of hickory! Still, a bokken shouldn’t hit harder than heavier slabs of iron/steel designed to actually break things, right? They’re practice swords (Deadly in skilled hands sure, but not nearly as much as a real weapon)
That’s just my opinion though–if everyone else is happy with it who am I to disagree?