I can keep playing this game, as can others. Why do we need all that money invested in data collection and disseminating cat videos, political unrest, etc.
Not at all clear.
FOSS before that likely made it fall as well
Almost certainly false. Imagine a world where the concept of open source never happened, so if you want a website you have to pay thousands of dollars for web servers, compilers, databases, etc. Would the demand for software developers be higher or lower than in our world?
We can only speculate about the future having more AI-code or the repercussions thereof (as many do).
And for me with musicians the number is zero.
You probably want digital payment systems like banking and warehouse management. But I am thinking those sort of areas are only fraction of modern software industry.