I really don't know what to do with those projects which I started confidently but then left when it was about to finish because I lost motivation

Make it FOSS, use a recursive acronym name, publish it in GitHub, make a few hundred of senseless commits changing just a couple of things in the comments. Then let it stagnant for a couple years. Now you can blame a leecher community that do not help neither appreciate your efforts. Now you have something to put in your CV
Profit?

I have so many of these abandoned projects.I normally only upload something I feel is slightly "polished" to GitHub so these abandoned projects just sit in my storage.

@zmzmuazzam98 same here, they're just lying on Hard disk