By analogy, any software project that includes writing a database is, de facto, a database project.
It's like a web framework. Coding one when CGI came out was way less work than now. If you want to match what django or rails does now, it takes years.
I read somewhere it would cost millions if you tried to hire dev to recode django at today's market rate.
I follow a project called Handmade Hero[0] by a longtime game and game tooling programmer where he codes a complete game from scratch with absolutely zero dependencies except Windows. It's an excellent educational resource and I've learned a lot about how games work, including game engines such as Unreal of Unity. This has enhanced my knowledge of how I might better use those engines and I feel that it's been a valuable use of my time.