At the time it was a BS conspiracy theory. There was some evidence for it, and some evidence against it and it happened that the evidence we had at the time was stronger for the non-lab leak theories.
That's what changed right now. We have new evidence that puts the lab leak theory above the others. Back when Trump was demanding that "China pay" and people were beating up random Asians who were just walking down the street, that wasn't true. Just because we today have the evidence to support the lab leak theory, that doesn't justify Trump's claims or the "blind faith" of his followers who rejected the available evidence to support what they wanted to be true.