A useful model for knowing how to best use your time is to think about how much your time is worth in terms of dollars. For example, if you make $20 per hour at your job, that’s a rough estimate of how you value your time.
But there are some pursuits where such a metric doesn’t apply. When I think about the time I put into writing I rarely think about it in terms of dollars. I do the writing, because I want to. It’s good for me and it seems to be good for some of the people who read it.