Long story short, it all started with an argument between me and a guy who thought only Japanese VN-related anything is usable normally, and that all Western VN-related software (Ren'Py included) are either clunky or laggy garbage. He also gave a Japanese novel engine called Light.vn (don't mind the link, it's the engine name) as an example (there is a killer feature in it: WYSIWYG editor). So I started my engine to prove him wrong.

After some time, I really saw that Ren'Py is not as fast as it was when I started to use it long ago. But that's because it uses modern Python, which is by itself not too fast and lightweight anymore.

That's why I write my engine in C and aim to make it much faster than Ren'Py and with better UX. Not speaking of a desire to create something meaningful myself.