Lua is my fifth favourite programming language and for good reason. I like its speed, its syntax and the fact that it is so simple. Lua is written in C and can be used for gamedev, webdev and sometimes even appdev.
My first time using lua was in my thulium esolang. I used it in the lexer and found it nice and I was able to use it to do what I needed with minimal setup.
I didn't touch lua again until I made chromium about a month later. I copied a lot of the code from thulium and in the end I got it done.
I would say that lua is a language good for beginners but not the best for framework programming (excluding gamedev). The syntax is at least somewhat intuitive and thanks to its small size it is quite fast. It is also good in scripting.
I like it mostly because of its applications in scripting (because I am not a framework dev) but its main weakness is the fact that it is... well... weak. It doesn't have much functionality in the world of webdev and appdevs usually favour languages like JS and Python as opposed to Lua.