Adaptions are a thing. However paying someone to do it costs a lot of money (even doing it yourself is not cheap) and it’s not much more - possibly even less - of a stretch to one’s budget to get a whole new car built from the ground up as an EV, so commercial conversions tend to be a niche market focused on more interesting vehicles (e.g. what this Melbourne based conversion company converts).
Economies of scale, i guess… Renault seems to have tried it, perhaps for internet points only though.
I can’t shake the feeling that the technology is there and attainable, but… money. Which means it only favors automakers.
GM had at one point been working on an eCrate block for conversions, but they seem to have abandoned it.
This looks like a real product.
I seem to remember it being insanely expensive though.