Yeah it's never been that, it's always been an editor-driven engine. Started life as a proprietary game engine by a consultancy, then open sourced about a decade ago.
Super cool though, learning Godot at 13 is a great opportunity.
EDIT: Sorry if I seem grumpy, I'm not actually grumpy at you, I'm grumpy at PyGame for calling itself a game engine when really it's just SDL + the ability to blend images.
I wouldn't call it one nowadays, except in so far that someone looking for an engine might find themselves happy with SDL (or PyGame, etc)
SDL is funny in that it kind of is an engine, à la Raylib, with SDL_Renderer (2D only), but most people use it just as a platform abstraction layer.
I've seen plenty of projects where people use it and reimplement things it already does because they want to minimize dependency. The entire point of using a library like SDL is dependency! Use all the things!
It's a bit more than that, especially the current version. You're right that it isn't an engine in and of itself but you could probably build a decent engine on top of it. SDL3 + WASM + Lua would be chef's kiss.