[DevKoala]

If I was evaluating multiple similar roles, and most offered salary ranges except a few, I would ignore the ones that didn’t offer salary ranges.

Your experiment is not valid because you are not controlling for the job market environment. However as the job market environment evolves to offer more data, the job postings with less data will suffer.

We already see this pattern in other markets such as housing/cars. More information makes the posting more attractive to the extent that there is whole industries dedicated to offering more information about postings, ex: carfax. The job market is not different.