Turning film cameras into digital cameras

Let's for the moment we think "out of the box". If there is a product
which has the shape of either a 35 mm or 120 film cartridge, and you
can just load it into your old film camera. However, this product acts
like a digital "film", in which it will store images in digital
format, instead of into film, would you buy such a product? It is
just exactly like your old film cartridge, put into the back of your
camera, set the camera as it has a film in it, advance the lever ,
take photos, go to next shot, etc. The difference would be when you
complete the shots (24 or 36 exposure), you connect this cartridge to
your computer and downloaded the digital data, just like a media card
in your digital cameras. This product would be re-used again and
again, just like the digital cameras.
Some of you may said that is the same question whether there is a
"back cartridge" that can be fitted into the old Hasselblad, Mamiya RB
or M645, in which it changes into digital cameras. However, I heard
that this speacil back is very expensive. Correct me if such a product
exist for professional photographers, but at a very high costs! (such
that it is just easier to throw away the old cameras and buy a new
digital one).
The next question is whether technically this is possible. Will people
buy them, and use their old cameras (which some had invested heavily
before the digital era came to play). This sounds like a crazy idea,
but I sometime wonder that if it is possible. There are lots of smart
people and inventors in this world, and I am sure they have the brain
to create such a product. I am sure that this would not be welcomed by
digital cameras' manufacturers, as it will compete with their product.
Although some of the "players" are still the same (Kodak, Fuji, Nikon,
Canon, Pentax, etc).
Unfortunately, we are living in a world which are driven by narrow
"track of minds", set by big corporations which decided upon our
direction into the future.
Thanks for sharing my "dream". I am now awake from my day dreaming.
Thanks for the discussion.