Was Lua ever in competition with Python? Lua was for embedded systems and integrated as a scripting platform for other products. That's a vastly different market and design purpose than a general-purpose scripting language like Python. What has Python actual won over Lua that any other language hasn't won?
I'm actually surprised JavaScript hasn't surpassed Lua for the kind of things Lua is designed for -- but Lua seems to hold on and people aren't generally embedding JavaScript as the scripting language for other programs.
I started using JavaScript in my latest window manager after first using Lua. Since it’s for macOS the JavaScriptCore framework was already built in and uses the latest syntax. Honestly I prefer JS now even for embedding as long as it’s on macOS. Dunno how easy it is to embed on other systems.
I'm actually surprised JavaScript hasn't surpassed Lua for the kind of things Lua is designed for -- but Lua seems to hold on and people aren't generally embedding JavaScript as the scripting language for other programs.