Steps on Cessnas
All the C150 I have flown have had them
Only the areobat C152's have had them.
All C172's have had them
Lucky I am not a short arse and can still get my leg up high enough so can climb onto the spar with out the step (although this has cost me a pair of jeans splitting). Although normally I only do my first flight in that plane then I go by time after that.
MJ