Development of video games is the final boss of this one.

If you want to kill someone's dream of publishing a game, encourage them to build their own engine from scratch. I cannot think of a more malicious piece of advice given how effective it is, statistically speaking.

The exceptions to this are so incredibly rare. Virtually all of the in-house engine work at indie scale has been replaced by Godot in recent years. It used to be something like 10-11% of studios were in-house fully custom. Now it's probably closer to 1-2% fully custom and 8-10% on Godot. Having a reasonably stable OSS option has removed the last major argument that I am familiar with for simply using what already exists.