So what you're saying is that an extreme instability of the tectonic plates underneath us incessantly colliding(just ignore the absurdity for a moment) would not have an affect on the ground directly beneath us?
Thats an entirely different question than your opening post . If you lived in a tectonically active area (like the Asian margin of the Pacific plate, or the Sunda Plate), your life would be quite "interesting" in that earthquakes could dominate your daily concerns. and many active volcanoes define the plate margins>There also exist several "supervolcanoes" where several plates conjoin at "Triple points".
BUT although the focus of earthquakes (epicenters and hypocenters) would be along those lines, the reach of the effects wouldnt be that far because of the following
1. the earths crust is rather plastic and doesnt support transmittal of devastating energy for great distances
2. PLates are veery thin compared to the even more plastic layers of the mantle
Seismic "Wave" propagation can be destructive , especially in the water , but the actual " Ground Wave" that contains the quake, gets damped quite quickly with distance, almost in a square root function. So, yes, the ground directly beneath you and directly within the effect zone of the seismic waves could be trashed by plate motion, but this energy dissipates quite quickly horizontally unless youre in the path of a seismic tsunami.
What you asked before in your opening post just does NOT occur, even as a dream theme. (Conervation of Mass still works) Weve got enough seismic data and 3D maps of their effect zones gathered over the last 100 years or more that we feel quite confident about the mechanisms.
I gotta say that the concept of "Tectonic plates" wsnt really developed as a tool until the 1960's, even though the data and evidence was being compiled by every discipline from paleo, tructure, paleogeography, to climate science ,as early as the 1920's. (Scientists can be very very conservative in their ability to just drop one thing and pick up another.) It took that final bit of defining an actual MECHANISM that took place in WWII that drove it home.
SOme of my own professors (In the 1970s) just quit their careers in geology rather than take up a whole new paradigm.