I mean, I worked with someone who creates a very high profile OSS project, and I'm sure it's a big reason he got hired to where he is.

I'll never say OSS is an optimal career path unless you are doing something extremely specialized (which to be fair, he is). But it sure can open doors for you even today if that's something you're passionate in. For me, I got around without any OSS, so it's more like a post-career plan now to help out some beloved repos.

(as long as you're not stupid, like showing your botting repository to an online game studio).