The rear steps are not used in ice or snow/slush due to slip hazard.
There are wide, gently gradient, side protected clean mobile steps; and then there are narrow, steep, open sided, clean a/c inbuilt steps. Which are safer?
I used to be amazed paramedic crews sometimes used the front steps rather than the rear ones. Seemed daft to me and dangerous. Some airports provide the wonderfully designed 'tractor track' wheel chair. And they still use the front steps?