they do, they are mostly for show. skateboarders wear knee pads.
People that played real football at ANY level with real full pads know that knee pads didn't really anything other than keep you from scratching up your knee on a poor surface. Football players want to be as light and unencumbered as possible.
when I actually PLAYED , you had to wear a cup , now it's not compulsory. sc
Why don’t players wear knee pads anymore? Seems kind of dumb not to protect the most vulnerable part of the body. Just ask McCree.