This is the infamous "stack fallacy" https://techcrunch.com/2016/01/18/why-big-companies-keep-fai...
The idea that the layer above your own is trivial to build (e.g. biology is just chemistry, or chemistry is just applied physics)
At some point I built a little 2d game engine, but the same amount of time would have been better served actually building a game in Unity. Eventually I solo developed a full 3d VR app for the MetaQuest.