When one knows writing a novel is preferable to writing a screenplay, or vice versa, then one may have the desire to pursue one of those literary forms, or both, if so inclined.
To pursue the dream requires careful research as to how to proceed, so one can consider the cost of proceeding.
As one knows how to proceed, and knows the realities of the market, then one decides if one should proceed and one asks questions like: Is it worth proceeding? Does one have the time? Does one make the effort?