This is kinda my point. You don’t seem to be coming at this from a position of much experience in the field but are confidently making assertions about it. You are confidently handwaving away what would be massive advancements in both materials science and manufacturing, all why saying it could result in an affordable fridge which would last for over a century. That’s unrealistic.
We can speculate a lot about advancements which might happen in many decades or even centuries in the future, but it’s foolish to talk about them with confidence, and it’s often irrelevant to the present.
> However, what's happening is that there just isn't much research into longevity.
That is patently false. The field of materials science and several branches of engineering deal with this constantly.
> There is low incentive to make cars last longer beyond a point, and the same holds true for products for the military.
Weren’t you originally trying to make the opposite point by using the B-52 as an analogy?