>Maybe unpopular opinion: only a relative handful of developers working on actually making game engines need the detailed control Vulkan gives you.
If you make a game instead of a game engine, you can use one of the existing engines.
If you make a game instead of a game engine, you can use one of the existing engines.
The other big push would be Epic cutting royalties until you're earning a significant amount, which would encourage studios not to hire or allocating as much resources to in-house.
In fact the "engine" part itself is quite small compared to the editor, and the hardest things can be done with third-party solutions, a lot open source: physics, rendering, audio, ECS, controls, asset loading, shader conversion.
The reason people gravitate towards Unity/Unreal is because of the low barrier to entry. This caused the monoculture among hobbyists.
The reason studios are gravitating to those engines is because of there is plenty of cheap labour available.