> You'd rather your vacuum be made of metal?

I would - rather it is. My grandfather had a kirby for decades. I've had a kirby for decades. Though mine has the transmission power drive that makes it a joy to use.

I can not imagine ever buying a plastic vacuum.

There are different plastics, some feel much better than others.

I bought a Dyson vacuum and it felt like cheap garbage, to the point that I returned it. I didn’t trust that it would hold up. It creaked and jangled around. The feel did not match the price tag.

Other plastic products, like the old polycarbonate Macs, felt very solid and well made.

Metal portions would be nice but i get it’s a weight thing. Also emphasis on it being cheap plastic rather than just plastic. Several parts of mine cracked and broke within a year.

Carbon fiber and 3d printed titanium is probably where I'd start for materials to design a high end vacuum to be light/strong/durable. Injected molded magnesium alloy would also be a candidate if production qty was high enough to offset the tooling.