HOW POWERFULL THE REAL EXPERIMENTS IN PHYSICS ACTUALLY ARE?

Taking into account the physical limitations as the uncertainty principle, causal decoherence, speed of light limit, etc? Naturally, the real experiment is considered to be the most powerful weapon of the scientist and yet there are substantial parts of the physical reality where real experiments are impossible to conduct, whether because of physical limitations or because of lack of money. What should be the right attitude towards the real experiments and their actual role in science? The growth of technology would undoubtedly reveal new ways of coping with the old problems and would make possible to perform some experiments which were unthinkable in the past. Yet, a lot would remain just physically impossible. Should then scientists start relying more on alternatives [like thought experiments, mathematical reasoning, etc.] or just sit and wait for the laws of nature to change?