Connections can be made but they're flimsy and I legitimately hate this as an idea because it just feels like a crappy handwave. Oh, sure, materia and spheres, same thing. Oh, sure, Shinra learned how to use the Farplane, basically Mako. The spacefaring point is really good and it is connected with the Farplane-Mako stuff: for humanity to forget how to create spaceships, there needs to be some cataclysmic event (hello JENOVA) but why would we forget only spacefaring and not, like, how to use Mako. It's possible both were conveniently rediscovered by descendants of Shinra but when you need to use the word "convenient" you know that this trout is bollocks.