Can OSB boards be laid as flooring on carpet?

When making an old house habitable, we are simply considering using OSB boards as flooring and leaving the existing old carpet underneath; basically as insulation.

Has anyone done this before?

Has anyone done this already?

Why would anyone do such nonsense? I know carpet under laminate - it's terrible. Why OSB boards as flooring and not proper flooring?

Inexpensive and natural product.

When making an old house habitable, we are simply considering using OSB boards as flooring and leaving the existing old carpet underneath; basically as insulation.
Has anyone done this before?

You might want to explain "making habitable" once, you could also dye the old carpet.......
Honestly......an old carpet harbors things that you definitely shouldn’t preserve like that.
The carpet must come out, and until you have really carefully installed an OSB floor, you have to put in real effort, especially at the joints and transitions.
Then you better buy very cheap laminate or something similar somewhere on clearance, which is also easy to install. Considering the carpet as insulation is already adventurous.

Affordable and natural product.

Cheap yes in terms of price per square meter, but including additional work more expensive than cheap laminate. And... eco-OSB (just check WHAT is actually in it!) and underneath a musty carpet, calling that natural is out of the question. Your carpet is guaranteed 101% not natural.

Affordable

More expensive than laminate. If it can be walked on barefoot, then much more expensive than laminate.

Natural product

True, except for the binders such as phenoplasts, melamine-urea-phenol-formaldehyde, or polymeric diphenylmethane diisocyanate. Look at the binder and consider whether you might actually want natural formaldehyde emissions from your natural product.

Affordable can also be reasonable. You want cheap and simple. Carpet always cushions and causes problems with the tongue/groove connection.

I wouldn't do that. On the one hand, it's a botched job to lay something over carpet. Besides, you want to get rid of an old carpet anyway, and OSB boards are maybe okay as the sole flooring for a walkable attic, but not for living space. My advice: remove the carpet. With a bit of luck, there are floorboards underneath that you can cheaply sand yourself, and then you have your affordable natural floor!