Ask HN: How can startups find so many AI-skilled individuals?

I've been closely observing seed-stage startups in Paris, and many of them (perhaps one in two) are currently looking for engineers skilled in artificial intelligence. This is quite new; it wasn't the case at all a few years ago.

What I don't understand is how these startups seem to be finding their recruits without much difficulty (otherwise, the salary offered would be much higher, compared to web development, for example). How is it possible that despite this strong and sudden increase in demand, the supply is able to keep up?

Have engineering schools anticipated this and trained all their engineers in AI? Have web developers managed a rapid career shift just with YouTube videos? Or is it that startups claiming to do AI are just connecting to APIs after all (and perhaps I could apply as a web developer too)?