10 years ago this sentence probably would have start a flame war. ;-)
Though it’s hard to imagine what the web would look like if the language had become the standard. JS is a pain but AS was even less suitable for general purpose compute.
ActionScript3 was a very suitable language.
But in browser, for now only the more limited JSDoc-style types can be shipped as-is indeed.
It's grown into a product of cults and attempted zingers rather than pragmatic or sensible technical discussions about what we should and shouldn't expect to be able to do with an individual programming language.
edit: to clarify, I assume there needs to be a basical level of comprehension of programming languages to debate the nuance of one, and if you can't think of a single reason as to why someone would want types removed, that's a possible indicator you don't have that necessary level yet, and I think the most effective way for you to learn that is to Google it. Sorry for coming across as rude if you genuinely don't know this stuff.
If you already know many reasons as to why types would be removed, then it seems disingenuous to ask that question, other than to make the point that you feel types shouldn't be stripped. If you think that, say it, and explain why you think they shouldn't be stripped.
Was it? Have you forgotten namespaces and enums?
These days, TypeScript will only add new features if they are either JavaScript features that have reached consensus (stage 3 iirc), or exist at the type system only.
There have been attempts to add type hints directly to JavaScript, so that you really could run something like TypeScript in the browser directly (with the types being automatically stripped out), but this causes a lot of additional parsing complexity and so nothing's really come of it yet. There's also the question of how useful it would even be in the end, given you can get much the same effect by using TypeScript's JSDoc-based annotations instead of `.ts` files, if you really need to be able to run your source code directly.
That's no less a build step than concating, bundling, minifying, etc. When people say "I'm against processing code before deploying it to a web site" but then also say "TypeScript is okay though" or "JSX is okay though," all they're really saying is "I like some build steps but not others." Which is fine! Just say that!
You're not actually suggesting that technology can't evolve are you? Especially one whose original design goals were to process basic forms and are now being used to build full-blown apps?
It's absolutely wild to me that with everything that has happened in the last 2 decades with regard to the web there are still people who refuse to accept that it's changed. We are building far bigger and more complex applications with JavaScript. What would you propose instead?
It was originally about build steps but now you're talking about it's design.
And your only response is to use a technology years away from being practical for most web apps?