There is the risk of tick transmission of Lyme disease in tall grass. I suppose you can pretreat to prevent contraction, but mowing grass means you don't have those threats/hazards to worry about.

I still hate lawns and wish more would be native, but I wonder if there's a way to grow a native lawn such that you invite the good wildlife and keep out the bad. Would need a biologist to chime in

My dog loves tall grass so much. He likes stomping them.