A couple of articles out right now asserting that three researchers at the Wuhan Institute of Virology were sick in November 2019. The original source of the claim is a U.S. intelligence report. First, if there is such a report I don't know whether it's accurate. If it is that is definitely suggestive (though not definitive proof) of a lab leak given the timeline.
Republicans seem to think that such a leak would support their theories that China developed the virus as a weapon and intentionally released the virus. It doesn't so I'll just ignore them. If their claim is that the idea of a leak wasn't investigated carefully enough because it could be politically contentious that's a possibility. There are a number of virologists who have been warning about the safety of such labs saying that while the risk of contamination might be low at each lab, cumulatively the global risk is quite high and constitutes a hazard we need to collectively address.
At no point during the pandemic would the information about the virus' origin have helped to eradicate the virus or deal with it medically. Knowing of its origin right now would help us make safety procedures at such labs and institutes a pressing global matter and transparency about what kind of research is taking place at each lab essential.
We know that at least 3.4 million people are dead because of this virus. Understanding its origins is crucial to helping prevent future incidents, particularly if it mutated in a petri dish instead of crossing over from bat to unknown intermediate species to human.
https://www.nbcnews.com/health/health-news/u-s-intel-report-identified-3-wuhan-lab-researchers-who-n1268327
https://www.wsj.com/articles/intelligence-on-sick-staff-at-wuhan-lab-fuels-debate-on-covid-19-origin-11621796228