I get that Linus is a superhero, but it's still so weird to me that this vital piece of the world's infrastructure relies on one man.
I think its better to think of it like a president or prime minister. He might set the plan and direction and making the big decisions, but there are thousands of others supporting and making the plan actually happen.
In the past he has delegated the release to others as well.
So if the worst would happen, the linux project would continue operating fairly seamlessly.
Relevant xkcd https://xkcd.com/2347/
It is a small bunch of people though.
OSS is heavily undermaintained, always has been. But the world hasn't exploded from it yet (somehow).
The kernel will figure something out. There are already lots of companies investing their own development resources into it. Would just need a new leader to emerge. Perhaps it'd be a rotating group of people who are responsible for managing a single release.
Tons of smaller but important projects don't have this luxury, though.
If you think OSS is undermaintained, you really ought to look at the way 90% of commercial software is developed.
It’s at least equally bad if not worse, with the added bonus that no one else can step in even if they really wanted to.
Wouldn't surprise me to see unmaintained software anywhere.