Yes, Java's type system "so weak". Just because many other popular languages have similarly weak type systems doesn't make them less weak. Also, as a long-time Haskell user, I can assure you that nullable types were nothing new even several decades ago. Perhaps you have only worked with object-oriented languages, where nullability is typically the default (which is a bad idea).

There are tons of languages with non-nullable types that are much older than that. C++, basically every ML-influenced language, Prolog, Erlang, Tcl.

A decade ago Idris, Agda, Haskell had been around for a time already, there hasn't been that much advance in 10 years. And a decade ago it was also a commonly argued that Java isn't getting a lot in return for its very basic static types, vs simplcity and expressivity that dynamic languages get.

I like Java, but that's weak argument.

We're in 2021, not decade ago.

What language sees wide spread use without at least a decade in gestation? Java, ironically, but cutting edge languages take longer than a decade before making it to the blue collar programmer's floor. I mean the number of people that struggle with even stuff like generics still is amazing and that has been around for 17 years at this point so 10 years is nothing.

And java has excellent static analysis, so if you want to you can prevent every single npe.