I believe all children should be allowed "risky play", or natural play using their imagination and doing everything you can possibly DO on play equipment or in nature. (Totally irrespective of how play equipment is "supposed" to be used")
I was in the playground last week, and I was sitting on a bench with my two boys, who were eating a snack before having a play. A few other mums were there, and boys aged 6,7 from my sons school.
Anyway, one mum kept chastising her son "Henry, get down from the seesaw, that is not how you play on a see saw. You are not supposed to stand in the middle". "Henry, dont climb the frame like that". "Henry, dont run on the grass". "Henry, you will fall." "Henry, you are going to lose your balance". "Henry, your shoes will get dirty". etc etc etc.
My boys started looking at me bemused, and went on to play. And did all those things she was telling her son not to do. I did not say a word, they were not doing anything wrong. But the mum gave me the cats bum face, and Henry came and sat down between us with a sullen look.
What use is a playground if you cant actually use your imagination and play? The equipment is there, you do with it as you want, and play with it as you want.
And yes, if nobody else is using the slide, I let my sons go up the slide. Climbing the ladder and sliding down is boring.