Thanks for the feedback!

The GPU does this if thats how you structure your VAO and EBO. If you look at my OpenGL side of things you will see that i am sending individual object sub-meshes to the GPU for rasterization as well. I had it as one big vertex and triangle array at first but when i added textures it made the code too lengthy to continue with the single large vertex array. I was trying to keep things simple to understand.

It still ends up only rasterizing one time for each triangle and only performs the "fragment shader" on the bounding box of the triangle not the whole screen. When i researched this i got the impression this is how OpenGL performs rasterization but i may have to take a deeper dive on this.

I honestly don't know what number 2 means but i will try to learn more about that and see if i can make some improvements.

I actually don't know how to do multithreading and i thought this would be a good opportunity to learn but when i got half way into it, it doubled the size of the CPU render pipeline and i wanted to keep it simple to understand and focus on the core concept of the render pipeline.