Seeing that as long as Y combinator has existed, only one company has ever gone public, the rest are still either humming along unprofitably, have been acquired, or gone out of business, the chances of most businesses having to worry about their largest business risk being an over reliance on AWS seems slim.
Yeah, nowadays it's done by dissolving the company or being bought out, then shut down.
Still, it's the same thing. Use of inadequate infrastructure being, let's say, terminated.