I am really trying to get on board, but I don't know what you mean. I see your anecdote about two different codebases and you found the C++ one easier, and I'm sure it happens.

> And here you demonstrate one of many problems - there's multiple null types

In JS, null and undefined are not meaningfully different unless you're checking for exactly one or the other. And there's little reason to do that. It has never come up for me that undefined made it through where null wouldn't have. But yes, you need to check if things are defined.

> In C++, there's only one null, nullptr. But most types can never be null

C++ absolutely has undefined, it just doesn't tell you about it. If I make a var with `int myVar;` it's undefined. There's no telling what it points to. But C++ will treat it as `int`. And it can be a lot worse. Vars can be memory represented as the wrong type. They can be truncated memory, dangling pointers, memory freed twice.

But with JS, if I access memory that wasn't explicitly set, it says "that's undefined." That's a good and explicit thing to tell me, and I can actually check for it. And the GC, obviously, avoids a whole class of cases where undefined would come up.

> This is actually one area where C++ was ahead of the competition

For the reasons above, I would say C++ is literally the worst option for null safety. Unless we define safety as "don't tell me this is undefined, even though it is."

> It's far too easy to make mistakes in JS and propagate them out

I'm just not sure why. I would say C++ has absolutely every footgun JS has and more.

C# introduced nullable reference types back in 2019, so it's been some time and now the vast majority of the ecosystem uses null-aware code. The only remaining warts are around a. codebases which refuse to adopt this / opt out of it and b. serialization.