Oh really? Well guess what, that's a huge benefit for Lua because its entire total size is around 500 KB. It's loaded into memory and executed start to finish faster than you blink. If you need a ‘standard library’, just use Penlight. As I already mentioned, vast majority of libraries for Lua are written in... Lua itself, because it's so goddamn fast. I'm using Fennel, the Lua Lisp that's transcribed on-the-fly, and it's still faster than Python. Lua is great for interactive tasks like desktop automation, e.g. with Alfred, Hammerspoon (which latter uses Lua throughout), or for scripting in Termux on the phone where Python would kill the memory immediately.

Lua's problems with the absence of popular libraries aren't because of any language issues (even the lack of null can be dealt with), but solely due to its non-adoption in the masses. It is very popular as an embedded language in gaming, though, and that's not a coincidence, because it fits that niche precisely because of its small size and extraordinary speed.