There’s a new law of the land taking root in Silicon Valley: the more technology makes us laypeople replaceable, the more the technocrats building it are considered indispensable.

That’s been good for the tech titans, many of whom are among the richest in the world and have watched their wealth and power grow alongside the rise of new tools like artificial intelligence. But it’s been more complicated for the companies they rule, saddling them with what’s known as key-person risk — when a single individual’s very existence is tied to an organization’s performance and value.