Why were attempts to detect the influence of the Earth’s motion on the results of a laboratory experiment

Why were attempts to detect the influence of the Earth’s motion on the results of a laboratory experiment made to test Einstein’s principle of relativity?

It is difficult to test the general theory of relativity, since in ordinary laboratory conditions its results almost completely coincide with what Newton’s law of universal gravitation predicts. Nevertheless, several important experiments have been carried out, and their results allow the theory to be considered confirmed. In addition, general relativity helps explain the phenomena that we observe in space – for example, slight deviations of Mercury from a stationary orbit, which are inexplicable from the point of view of classical Newtonian Mechanics, or the curvature of electromagnetic radiation from distant stars when it passes in close proximity to the Sun.
In fact, the results predicted by general relativity differ markedly from the results predicted by Newton’s laws only in the presence of super-strong gravitational fields. This means that for a full-fledged test of the general theory of relativity, either ultra-precise measurements of very massive objects or black holes are needed, to which none of our usual intuitive ideas are applicable. So the development of new experimental methods for testing the theory of relativity remains one of the most important tasks of experimental physics.