Edit: name checks out.
>It makes the pandemic deterministic
I don't understand why determinism comforts you, but you do you. Unfortunately, a lab leak is totally stochastic, and I hope this revelation doesn't keep you up at night.
>It's a popular topic ... because it moves the pandemic back into ... policy, etc. It becomes a human problem with human solutions.
Zoonosis is a wet market hypothesis, not a random encounter. China failed, and continues to fail, to ban or regulate the wet markets to solve the problem. Zoonosis is clearly policy and human problem.
>It appeals to the contrarian mindset.
The lab leak appeals to anyone who groks statistics. Wet market zoonosis could happen at any one of 40,000 Chinese wet markets. But a lab leak could only happen at one of ~2 Chinese laboratories. Zoonosis happens more overall, but lab leaks are more probable in the direct vicinity of the lab specializing in collecting and studying samples of this exact family of viruses.
>finding the source of spillover events is the work of decades
The reservoirs for both SARS and MERS were found quickly with much less interest. The probability of the lab leak increases every day that we don't the reservoir. Worse, at this point even finding a reservoir isn't definitive, because we would need to establish that the reservoir predates the pandemic, and that it didn't spillover into the animal population from humans.
Given all publicly available information, the lab leak is far more likely. The uncertainty is very high, because China destroyed or concealed the data. Unless someone's memoirs leak it in 50 years, it's unlikely that we'll ever know.