Again, it's a theory that has so far no basis in science - it's speculations, mostly by people who have no virology background. They maybe even PhD in other biology fields, but having them present their opinions, with no actual data to back it as facts, is as valid as database experts applying their intuition to reason about how to build ML models.

Meanwhile, viruses jumping spices is extremely well document behavior, and COVID like viruses are known to exists in other mammals. Actual data, and Occam's razor point to lab-made virus being invalid theory. Can experts pursue it? Sure, but until they have actual data, presenting it to the general public is click bait fear mongering.

And you also conveniently ignore that OP also had issues with vaccines, which effectiveness have as much backing by science as any theory could possibly have.