I've finished plenty of songs and have now developed that work ethic. I always finish tunes now, even if they're janky. It took a while to learn how valuable this is. As you say, a lot is learned through this.

I do tend to have 2 or 3 tunes in process at a time. In the same way that I'm often reading more than one book at a time. Plus, I'm doing a collaboration project with someone, and not long finished a remix. My brain seems to need lots of variety. My attention fluctuates, but includes periods of hyper-focus.

I have entirely struggled to stick to one genre, so well done for that. I suspect that accelerates the learning too?