I remember taking baths with my brother and sister when we were all small enough to fit in the same tub. Sometimes we'd play mad scientist chef with the empty shampoo bottles, or we'd play "shaving" - spreading bubble-bath foam over our legs or our faces and wiping it off in swathes at a time. What fun! disappearing and reappearing! It's as if we were grown up. This is what mom does. This is what dad does.
I never actually graduated to shaving with sharp things. The appeal is no longer there. What a hassle, what a bother, what a symbol of oppression! What an unnecessary chore.
Likewise, the child with a toy lawnmower. What does he perceive? Loud noise! Loud noise is fun! And what else? It's sunny outside! And look: there's someone walking back and forth (brrrm brmmm brmmmmmmm) for hours - they're a grownup, they must know what they're doing. And look: the little colored balls inside go poppety poppy pop pop when he rolls it along. Neat!
Next time you see a baby, catch its eye. Now make a face. Kids mimic. How do you think they learn what it is to be human? They don't ask (until they're a bit older) for the activities they mimic to make sense: they make their own sense (out of their keen and wondering senses or later from stories).
There is a long history of toys that are miniature versions of adult implements: bows and arrows, hobby horses. Such toys are aids to the imagination, which i guess we wise grownups don't need anymore.
And one more thing: even children who hate school have been known to play "school." The fun is in the play, the representation, not the thing represented.
On the other hand
Barthes has an interpretation of such toys which is more like yours:
faced with this world of faithful and complicated objects, the child can only identify himself as owner, as user, never as creator; he does not invent the world, he uses it: there are, prepared for him, actions without adventure, without wonder, without joy. He is turned into a little stay-at-home householder who does not even have to invent the mainsprings of adult causality; they are supplied to him ready-made: he has only to help himself, he is never allowed to discover anything from start to finish. The merest set of blocks, provided it is not too refined, implies a very different learning of the world: then, the child does not in any way create meaningful objects, it matters little to him whether they have an adult name; the actions he performs are not those of a user but those of a demiurge. He creates forms which walk, which roll, he creates life, not property: objects now act by themselves, they are no longer an inert and complicated material in the palm of his hand.
Granted, nineteen children given toy lawn movers will never use them for anything other than their "purpose" - and then leave them lying in the dust. But what Barthes forgets, and is too often forgotten, is that one of the benefits of childhood
is that things are not wedded as tightly to their meanings. That twentieth child might mow for a while, then imagine the toy is a dog on a leash, a magic fairy detector, a sand-castle-destroying goliath. This imagination is not totally aborted, as Barthes might say, by complicated, predefined toys: these merely limit the scope
of the imagination, and do not destroy it.