I think whats more likely to happen is patches & forks stop being shared. If AI continues to improve, I see a world where people are mostly no longer making software for others, but purely for themselves.

I've done it, personally. I've made all kinds of little utilities for myself kind of like a woodworker making their own jigs. While not purely "vibe coded," AI has let me actually finish a ton of personal projects that have been in my "eh, maybe I'll get to that someday" list. Now that there is very low marginal cost to make these tools, they can be highly specific, and they aren't all that useful to others unless someone else has the exact same problem as me, and well if so they can try to vibe code their own tool.

We'll get to a point where most of the open source projects are reserved for large scale infrastructure, as a cathedral not a bazaar, and then the vast majority of end-user level software will be highly personalized, custom utilities that generally aren't shared.