Gave a look into Godot, find out the engine is deeply integrated with some custom scripting language that leads to performance issues [0] (Unreal learnt from this and got rid UnrealScript), support object-oriented design over ECS [1] and are still trying to support OpenGL when the rest of the industry is dropping it in favour of focusing on modern APIs like Vulkan [2] but progress is at least being made with Godot 4.

[0] https://sampruden.github.io/posts/godot-is-not-the-new-unity...

[1] https://godotengine.org/article/why-isnt-godot-ecs-based-gam...

[2] https://forum.unity.com/threads/opengl-deprecation-and-remov...