> runtime exceptions are not the solution

They are part of the solution.

Good programming needs to handle errors. Monadic error-handling gets you most of the way, combining the local reasoning of return values with the terseness of unchecked exceptions.

But there are simply too many places where something can go wrong to try to enforce deliberate error-handling everywhere. TFA mentioned indexing into arrays. Integer operations resulting in overflow is another example. To stay sane these fails just have to come out exceptionally.

People writing about Java got it right for a long time: "Exceptions should be used exceptionally". But just like "null is the billion dollar mistake" it hasn't made it into the way people program yet.