Does it seeming feasible make it inevitable?

I happened upon a nifty video by the Curious Droid (if you like old NASA stuff, you’ll want to check out this guy’s channel) that lead to another classic.
It looks back at some of the big dreams of the 50s and 60s and how they played out in the face down to Earth realities.
I’m fascinated by this stuff because I remember it from my own childhood and frequent visits to the Chicago Museum of Science and Industry to gaze upon the dioramas and then I waited and watched to see what would come to pass.

The Biggest Rocket ever Designed? - The Sea Dragon Nuclear powered Planes, Trains and Automobiles

I don’t think it is always the case that things that seem feasible inevitably come into being because there can often be hidden problems that are not evident until development takes place.
Antibiotics comes mind here where the development of substances to combat infections has led to strains of bacteria becoming resistant to treatment.