Did you know that for every number there is in fact a larger number?

The Chips bill meant to boost semiconductor fabs in the US was for 280 billion. And that wasn't even to get on par with what Taiwan was making.

17 billions is pretty small change in setting up your own ram manufacturing.

Fundamental computer hardware like cpu/gpu wafers and the stuff that goes into RAM is EXTREMELY hard to make at all, let alone at any remotely competitive level. And the people currently running it in the world have had a LOT of time to get VERY good at it.

Instead of tens of billions, you'd need hundreds of billions just to get started. Plus, Valve probably doesn't want to try to compete and then get destroyed by one of those companies, essentially killing themselves in the process. They probably generally want to just stay in their lane and not overextend. They just started supporting a brand new entire operating system now, and that's probably enough, for now. Maybe in the future if everything is really successful?

Try that argument at work. "Guys, we made enough money this year!"