A few examples: https://handmadehero.org/ https://ourmachinery.com/post/physical-design/
Simple libs widely used in game dev circles: https://github.com/nothings/stb
This one is a full game engine with tools made for educational purpose: https://www.raylib.com/
I do write games and game engine code and tools in C++ without using any of the OOP features.
I know quite a few of other professional, experienced and talented developers doing the same, even full AA studios with up to 50 employees.
Some of them are going back to procedural C after a few years of disappointment with OOP madness.
I'll publish articles about this later, but for now, all I have to say is that it just works.
Newbies are often afraid of manual memory management and pointers, but there are simple ways to avoid shooting yourself in the feet with those.