They are not principally data-driven:
For decades, it was believed that our simple model of the early universe, characterized by a small number of parameters, was naive and the result of scarce data. By the turn of the 21st century, we had collected enough to verify that the universe indeed started from the simplest possible initial state, being nearly homogeneous and isotropic with small fluctuations that developed into the complex structures we find in it today. This simple cosmological model, which has existed for a century, is the foundation for modern cosmology.
In today’s fierce job market, fledgling scientists sometimes attempt to impress their senior colleagues with lengthy derivations marked by challenging mathematical complexity. Another postdoc told me recently: “The most fashionable trend for demonstrating exceptional skills in my research field involves writing extensive papers, sometimes hundreds of pages long, or longer. I am facing the strategic dilemma of choosing between two options for my future career: long complicated projects or short insightful papers?”
It is clear that accomplishing long projects requires more sweat; but is science supposed to be hard labor? Not necessarily. Our task as scientists is to explain phenomena based on the simplest theory whose predictions can be tested further by new experiments. And in the spirit of Occam’s razor, if the answer is simple, why make it complicated?Abraham Loeb, “The Simple Truth about Physics” at Scientific American
If he thinks evidence is important, that should rule out the multiverse.
Note: Abraham Loeb is the Harvard astronomer who spotted Oumuamua, a space rock, passing through the solar system in 2018 and raised the idea that it might be an extraterrestrial light sail. See: Astronomer: We’re Too Dumb To Think Space Object Oumuamua Was an Extraterrestrial Lightsail