How? I barely have enough time to do my day job. You think I have the time or expertise to research the origins of a virus?
Where does it end? Do I grow my own food? Make my own clothes? Build my own car after mining ore, smelting it and doing a million other things?
Trust the experts if you've no time for more, but this is the likely result.
Put time into your own research, and maybe you won't be caught off guard.
Why? What guarantees are there that I'll do a better job of research than the experts?
The "experts" rarely have a unanimous consensus on anything. If you actually listen to all of the experts, you'll hear all of the possibilities. But that still won't tell you who's right and who isn't.
On a question like "lab leak or meat market?" the answer isn't of importance to me, or any other average person. It's important for the experts to know the truth, in order to be able to prevent it next time. But other than that, finding someone (or several someones) to pin it on isn't going to give everyone the past 15 months of their lives back.