What is the value in this kind of speculation? I think that it can help provide direction for future research. If we think these soda lakes were the cradle of life, then we could look for remnants of early (even though finding that is quite unlikely). We could also try to replicate (steps of) abiogenesis in the lab in conditions mimicking soda lakes and plausible variations thereof. If that yields promising results it could inform exobiology speculation, and as to the purpose of that speculation, it could inform where we send probes in the very long term.