I played around with it a couple years ago (https://minimaxir.com/2016/12/primitive/) and it worked out surprisingly well.
In case anyone is interested, the code is on GitHub .
The comparison is interesting since your rectangle version has superior image quality compared to Alsings. If I squint my eyes it is hard to tell a difference to the original picture. It looks blurred the "right way" somehow.
Only the UI is closed source. It's written in Objective-C and basically shells out to the Go code.
Edit: Also, if you would like some help maintaining it, I imagine plenty of fellow HN-ers (including me) would love to help.
Is this noticeably better than Vector Magic when using Bezier curves?
Maybe I will finally be able to get rid of it. I can't tell right now, I think Primitive is being hugged to death currently.
But results are still pretty nice even at low quality setting with limited colour palette. Hardly takes 15 secs.