I think the worst thing that could happen to game development is that all games would standardize on the same things.
I also think that not every game can be successfully implemented on every engine. An engine is more than just the graphics you are looking at. Every one of those engines come with a full implementation of scripts, editors and interfaces that simplyfy your development but also restrict you.
As such most usages of the engine result in a modification of these restrictions to cater more to the needs of the game.
An RPG does require different facilities from an engine than an FPS or an RTS or a space sim does.
It's good that there are still some out there who take new approaches and do not adhere to standards. The ogg format would have not existed if everybody would have stayed on the MP3 standard. The reason ogg is popular in games is that it results in smaller files.
In contrast to that I also think that it requires a lot of effort to create a decent engine. I think what Larian Studios would like is to use their current engine and replace the 2D part with a full 3D implementation. Which is still a daunting task even if they use the 3D graphics part of an existing engine.
