No, it wasn't just simpler. The heliocentric model explained the orbits more precisely. Check out Kepler.
If we were to go by the idea that elegant explanations with no predictive power were science, then I propose a "theory" which by gravity is conveyed by magic invisible elastic bands that are attached to everything in the universe. And I'll write equations and come up with rules that will make the behavior identical to what we see observed. If you find a problem, I'll just update my equations accordingly. We could do that back-and-forth forever and I can hold on to my "theory" forever.
No, to find out if my theory has any merit, we need to show some way in which looking at the world through my theory provides a better understanding, a more precise model, and not just an appealing idea. Elegant ideas can provide useful inspiration for scientific exploration, but if they don't make any testable predictions they are just dreams, no more true or false than fairies. The foundation of science, as opposed to every other system of knowledge is it's brutal testing of ideas against reality.
String theory, as far as I've read, provides no insight into the behavior of anything, and thus we simply can't tell if it's real or not. It might as well be fairies.