Why do these mass layoffs keep happening in the software industry? Or is this a global phenomenon that exists across all industries?
Only to a small extend. Mostly it happens in software. And no it's not just "overhiring" (that doesn't happen across so many industries). That's only part of it. We all know with AI we won't need white collar jobs anymore. If I had children I wouldn't allow them to study CS. Not anymore.
I don't have better data than you, but I'd be very much surprised if AI would replace computer scientists rather than being a tool which will change what we'll have to be good at as computer scientists.
There is a lot of digitalisation to be done and AI might change the price of doing that, but it won't make a whole academic discipline obsolete.