This sounds entirely too doomer.
There will obviously be companies that build a vibe coded app which too many people depend on. There will be some iteration (maybe feature addition, maybe bug fix) which will cause a catastrophic breakage and users will know.
But there will also be companies who add a better mix of incantations to the prompts, who use version control and CI, who ensure the code is matched with tests, who maintain the prompts and requirements documents.
The former will likely follow your projected path. The latter will do fine and may even thrive better than either traditional software houses of cheap vibe coding shops.
Then again, there are famous instances of companies who have tolerated terribly low investment in IT, including SouthWest Airlines.
I'd say you're absolutely right.
The problem is...what is the distribution of companies who do it "right" to companies that don't?
The same as the distribution of companies which are profitable over time and grow steadily, vs the others which clumsily flail around to somehow stay alive. To the winner go the spoils, and the winners will be a tiny fraction of companies, same as it ever was.
A way I look at it is that all net wealth creation in public companies has come from just 4% of businesses:
https://papers.ssrn.com/sol3/papers.cfm?abstract_id=2900447
https://www.reddit.com/r/investing/comments/rk4udc/only_4_of...
It'll be similar with software companies. 4% of them will hit on a unique cultural and organizational track which will let them thrive, probably using AI in one form or another. The other 96% will be lucky to stay alive.
Same as it ever was.