I want to skip over the static typing benefits argument, because I think it
is well understood that static typing is a good thing and if we could bless
JavaScript with a built-in and robust typing system then I don't think many
people would be against that.
Well, yes. That's what Typescript is. If a built-in and robust typing system were added to Javascript, it would be the same thing as integrating Typescript into the ECMA spec. for Javascript.
EDIT (some more thoughts):
For example, a new package you install can require a new TypesScript
version. Once installed, you then may need to update your source code. This
can place quite a high tax on the developer, where perhaps a 10 minute
change becomes hours long.
Yes, that's not very different than upgrading to a new version of e.g. Python or Ruby on the back end. The problem is that you're seeing Typescript as "just a framework", rather than a compiler/interpreter. If you view upgrading Typescript versions the same as e.g. upgrading Python or Ruby versions, and plan for it accordingly, then you'll at least have the correct expectations regarding the scope of work, even if the actual work to do isn't any less.
Most libraries do not document their types, or have no examples using
TypeScript.
If a type system were integrated into Javascript itself, it would have to be optional, in order to maintain backwards compatibility with the vast untold billions of lines of Javascript that are out there. Thus, you'd have exactly the same problem. It's very difficult to add a typesystem to a language after the fact.
Errors are long and don't provide enough detail. They will explain a type
mismatch referencing many types you may not have ever seen, and are not
documented anywhere. Except for simple errors, many of them are very hard to
follow to a remedy.
Poor error messages are an issue with any type system that allows generics. Typescript's error messages are, at least in my experience, better than C++'s error messages. I find this remarkable, given that C++ was designed as a typed language from the beginning, and Typescript has, as one of its design constraints, strict backwards compatibility with Javascript.
I referred to TypeScript as a framework which it isn't. However it feels
similar to me in that you are at the whim of TypeScript developers and how
they decide to progress with the language.
That's true of any programming language, Javascript included. If you're writing Java, you're at the whim of Oracle. If you're writing C#, you're at the whim of Microsoft. If you're writing C++, you're at the whim of the C++ standards committee. If you're writing Python, you're at the whim of the Python Steering Council (and you used to be at the whim of Guido Van Rossum). Every programming language has some person or committee that's in charge of it, and if you're choosing to use that language, you're implicitly accepting the decisions made by that person or committee.
EDIT (some more thoughts):
Yes, that's not very different than upgrading to a new version of e.g. Python or Ruby on the back end. The problem is that you're seeing Typescript as "just a framework", rather than a compiler/interpreter. If you view upgrading Typescript versions the same as e.g. upgrading Python or Ruby versions, and plan for it accordingly, then you'll at least have the correct expectations regarding the scope of work, even if the actual work to do isn't any less. If a type system were integrated into Javascript itself, it would have to be optional, in order to maintain backwards compatibility with the vast untold billions of lines of Javascript that are out there. Thus, you'd have exactly the same problem. It's very difficult to add a typesystem to a language after the fact. Poor error messages are an issue with any type system that allows generics. Typescript's error messages are, at least in my experience, better than C++'s error messages. I find this remarkable, given that C++ was designed as a typed language from the beginning, and Typescript has, as one of its design constraints, strict backwards compatibility with Javascript. That's true of any programming language, Javascript included. If you're writing Java, you're at the whim of Oracle. If you're writing C#, you're at the whim of Microsoft. If you're writing C++, you're at the whim of the C++ standards committee. If you're writing Python, you're at the whim of the Python Steering Council (and you used to be at the whim of Guido Van Rossum). Every programming language has some person or committee that's in charge of it, and if you're choosing to use that language, you're implicitly accepting the decisions made by that person or committee.