Cages aren’t always gentler on legs.
When I was a teenager I cut the back of my leg with the cage of an Odyssey Black Widow. If I remember right the cage was cromo so it was thinner/sharper/grippier than aluminum.
I was wearing shorts and the cut was behind my knee so I could see the wound open and close with every pedal stroke on the way home.
I do think flats with pins have more grip and are more comfortable than caged pedals.