Comment by xandrius

Sure, here are the "steps" for creating that from scratch:

1. Setup lighting 2. Create a mesh importer system 3. Create an animation runner system 4. Create your 3D models + all animations needed (walk forward, crouch, run, jump, death, etc.) 5. Setup a camera system for following your character 6. Setup a physics engine for your character 7. Add support for collisions and high speed elements (i.e. Bullets) 8. Setup an AI system 9. Setup a particle system 10. Setup a player input system 11. Setup a save/load system

Follow those and you should be able to get from 0 to hero in a few years. Or you can use an engine and do it in a weekend.

I might have missed a step or twenty but people who want to avoid engines usually end up spending most of their time building an engine, and basically re-doing all things engines already provide.

And yes, making a postgres backup is orders of magnitude easier than making "just" a game, even the most basic one.