I'm reminded of the story of Randy, that I watched unfold over quite a few months - he couldn't help himself but to work on new features, rewriting existing features, hacking to make his workflow better, but really struggled to release anything, like a form of bikeshedding where you are actually still productive, except what you produce doesn't seem to meaningfully get you closer to shipping at all.

The videos that document the journey probably haven't gone anywhere:

https://www.youtube.com/@randyprime/videos

https://www.youtube.com/@randyprime2/videos

If you want to make an engine and learn about making engines - make an engine.

If you want to ship a game - think long and hard about whether an off-the-shelf engine wouldn't be a better investment of your time (because you wouldn't invest hundreds or thousands of hours making something bespoke and could actually make the features you need within an existing engine).

I suspect that with the great FOSS and source available engines we have, like Godot, there will be plugins for msot things and folks will be able to make their own without having to start from scratch (unless they really want to), like the most competent terrain implementation for Godot so far is a plugin - https://tokisan.com/terrain3d/

Hell, maybe also contribute to lesser known engines if you feel like it: like jMonkeyEngine, Flax (it's great, like a lightweight and 3D oriented Unity / Unreal with a footprint closer to Godot and a nice C# integration), Stride and others.