Crawling on hard wood floors

Anyone’s babe crawling on hard wood floors? We’ve got a house on a cement slab with thin hard wood on top. It’s by no means comfortable to stand on so we’ve put a rug down for the baby in the living room area (open concept house). I think she’ll be fine by others have voiced their concern about it hurting her knees. My theory... if we’ve made it to 2020, then we should be fine. Am I too chill about this or does everyone else need to relax a little?

Thanks!