Ask HN: What value do fractional CTOs provide?

I don’t understand the value add of some random technical person you barely know, who doesn’t believe in your mission like a CTO should, for the vast majority of startups.

Seems like a great way to make unfocused progress that is more harmful than good. Also a way to shift blame of the startups misgivings onto an another person. Are there any successful startups that started with a fractional CTO?