The two great 20C physical theories are relativity and Quantum mechanics. There is also a well-known history of relativity skepticism for various reasons. Some of this continues today, as with this list of Counterexamples to Relativity.
I am coming to the view that skepticism about quantum mechanics is 100x greater. Every month papers get published in reputable physics journals that question aspects of the theory that I thought were settled in 1930. The issues involve interpretations, ontology, foundations, or some paradox. I guess there are occasional arguments about the relativistic twin paradox, but no reputable physicist would waste time on an issue that was settled a century ago. And yet reputable physicis do waste time on silly quantum paradoxes.
Einstein was famously a quantum skeptic, but the consensus at the time was that he was wrong. I am going to post more about why I think physicists are wrong today.