Indeed. These products need no R&D really and I consider VC funding them a variant scam, except with private funds.

However, try to VC say a factory manufacturing metal parts or plastics, nobody will say yes...

Heck, try making actual cars or even golf carts on VC money. VC funders are either interested in something completely not speculative and small (eg. EU VC scene) or total moonshots in badly understood markets where no actual R&D is required.

If the thing is very speculative research, most VC aren't interested.