Writing your own engine is getting to be a harder to justify decision given the affordable availability of these high quality engine options but there are still

Writing your own engine is getting to be a harder to justify decision given the affordable availability of these high quality engine options but there are still situations it can make sense. All these engines make some efficiency sacrifices for generality and feature set. You can get better performance if you have a specific problem to solve and you design your rendering around it. For many games that's not going to make sense but for certain VR applications it still might. For my VR projects I've gone down both paths and there are pros and cons to each. For many projects though the biggest advantage of these engines are the editors - writing your own rendering engine for a specific use case is a lot less work than building an editor that can compare to these tools.