Well, apparently there is a loose scientific consensus but still plenty of debate, summarized in this article in The Atlantic.

Before the asteroid hypothesis took hold, researchers had proposed other, similarly bizarre explanations for the dinosaurs’ demise: gluttony, protracted food poisoning, terminal chastity, acute stupidity, even Paleo-weltschmerz—death by boredom. These theories fell by the wayside when, in 1980, the Nobel Prize–winning physicist Luis Alvarez and three colleagues from UC Berkeley announced a discovery in the journal Science. They had found iridium—a hard, silver-gray element that lurks in the bowels of planets, including ours—deposited all over the world at approximately the same time that, according to the fossil record, creatures were dying en masse. Mystery solved: An asteroid had crashed into the Earth, spewing iridium and pulverized rock dust around the globe and wiping out most life forms.

Their hypothesis quickly gained traction, as visions of killer space rocks sparked even the dullest imaginations. nasa initiated Project Spacewatch to track—and possibly bomb—any asteroid that might dare to approach. Carl Sagan warned world leaders that hydrogen bombs could trigger a catastrophic “nuclear winter” like the one caused by the asteroid’s dust cloud. Science reporters cheered having a story that united dinosaurs and extraterrestrials and Cold War fever dreams—it needed only “some sex and the involvement of the Royal Family and the whole world would be paying attention,” one journalist wrote. News articles described scientists rallying around Alvarez’s theory in record time, especially after the so-called impacter camp delivered, in 1991, the geologic equivalent of DNA evidence: the “Crater of Doom,” a 111-mile-wide cavity near the Mexican town of Chicxulub, on the Yucatán Peninsula. Researchers identified it as the spot where the fatal asteroid had punched the Earth. Textbooks and natural-history museums raced to add updates identifying the asteroid as the killer…

While the majority of her peers embraced the Chicxulub asteroid as the cause of the extinction, Keller remained a maligned and, until recently, lonely voice contesting it. She argues that the mass extinction was caused not by a wrong-place-wrong-time asteroid collision but by a series of colossal volcanic eruptions in a part of western India known as the Deccan Traps—a theory that was first proposed in 1978 and then abandoned by all but a small number of scientists. Her research, undertaken with specialists around the world and featured in leading scientific journals, has forced other scientists to take a second look at their data. “Gerta uncovered many things through the years that just don’t sit with the nice, simple impact story that Alvarez put together,” Andrew Kerr, a geochemist at Cardiff University, told me. “She’s made people think about a previously near-uniformly accepted model.”