There have been recent advancements in the hypothesis you may find interesting:

https://phys.org/news/2021-02-asteroid-crater-case-dinosaur-...

We can of course continue to look for disconfirming evidence, alternate explanations, or Incontrovertible Signs That God Is A Prankster, but come a certain point and the focus becomes one of refining rather than overturning theories and models.

It’s rather arrogant as a species for us to believe that enough evidence remains tens of millions of years after something like that happened that we can come to a conclusion. For all we know, a pandemic could have swept across the globe and killed all the dinosaurs and there would be no way for us to detect it.

Occam's razor suggests:

1. Such a pandemic (or other calamity) occurring simultaneously with overwhelming evidence a catastrophic asteroid impact is exceedingly unlikely.

2. Cross-species pandemic resulting in mass extinctions are similarly unlikely. Boom-bust population cycles perhaps. Mass cross-species extinction not so much.

3. Patterns of extinction (and survival) far more closely match the presently-accepted conclusion.

4. Precisely because an infectious agent leaves few multimillion-year traces, any defence of such a hypothesis can advance no further than "it might have happened". This is not evidence-based argument. (Traces of pathology might be preserved in fossil or amber substrates.)

Point remains that multiple highly consistent widely-distributed lines of evidence point to the asteroid hypothesis.

One unsubstantiated Hacker News comment points to the epidemic scenario.