[JonChesterfield]

There are loads of libraries for lua. You can either get them from luarocks in modern fashion or as more ad hoc source code in the old school. They're either written in C, against a stable language API, or in lua. Or a mix, doesn't make much difference. Also you can splice them directly into lua itself, e.g. the interpreter I use has libuv and sqlite built in.

The argument against shipping everything with the language is that the standard library is where code goes to die. Once shipped, fear of breaking users tends to block all progress. See mature languages like python and c++.

And regarding lack of innovation, lua has coroutines in the base language. Real ones that don't need co_await written near them. It has a module system built on dictionaries. It ships the compiler, so writing source code that you eval on the fly works out of the box.

Lua is spectacularly good. We are blessed to have it available.