I joke about never having finished anything, but the truth is that games is my hobby not my day job. The code I write for my day job is a lot like a game, hell it even uses SDL2. We programmed everything in-house because we all knew from past jobs that off-the-shelf solutions often caused more pain than ease.
My actual thoughts on game engines and whether or not to make them is written in this comment.
There's a ton of very successful wonderful things made in Unity, Unreal, Custom Engines, Custom Languages, Fantasy Consoles, Commodore Flash Carts, Cohost CSS Hacks and TI-83 Calculators. None of those things ever benefited from being told they should be doing it a different way.



