they provide real cushion so your knees aren't taking an absolute beating. the ky3's have 0 cushion unless you believe that zoom unit in the heel is doing absolutely anything lmao.
the closest thing you'll probably find is boost cushion in the hardens, but that's even a really slim amount of boost in comparison to ultraboost and pureboost. if you have different pairs of shoes for specific things, like one pair for basketball, one for running, one for work, one for casual wear, they will all hold up for longer and look better. it's worth the investment. also a good idea to get a new pair of trainers for running every couple of months if you want to take care of your body.
if you aren't running mass amounts of miles i guess you won't notice it as bad, but i can't even imagine forcing myself to run 4-5 miles in a pair of kyrie's