> I just want a fast programmable text editor with a native GUI and good defaults.
It's called TextAdept. Much of it is itself built on its own Lua extensibility story, which runs on a fairly compact C core. Both native GUI and terminal versions, using the same user config (keybinds etc). Linux, Mac OS, Windows builds. LSP support built in. Plenty of community-produced extensions around (but of course not as vast a range as VSCode's VSX eco-system furnishes).