If that were true then we'd still be using that technology. Instead we have independent suspension, rack & pinion steering, AC, heat, radio, defrosters etc.
Don't get me wrong I love those old rods you posted as much as the next guy. There is something truly special (and a little bit magical) about a period correct auto.
However, if I were to acquire a basket case first gen. Charger (my favorite) I would very likely put in a modern 6.1L, steering, suspension, AC, and sound system. And I'd drive it every single day with no fear of killing its value. It would look very stock from the outside, but it would not be.
I would not however, alter a perfectly good (running/driving) period piece regardless of engine package. I'd repair what needs repairing, and that would be it. I would drive it less often maybe, but enjoy it just as much.
I believe resto-mods and other custom pieces have an important place in the automotive world. Whatever it takes to keep them on the road.