I really hope Unity raises tons of money , and inspires some decent competition here.
Unity is the worst game engine, aside from all others. UE4 is a convoluted mess. I've tired several times , but even getting it setup with the C++ build chain is a pain.
Godot ( which epic funded recently ) isn't done yet.
I'm going to stick with Unity until someone else can build an easy to use game engine. Ultimately Unity does tons of very difficult things, like I wouldn't want to write build systems for a half dozen platforms solo.
The asset store is easily Unity's greatest advantage. With about 1000$ and a month you can make a full playable games. I also owe Unity my career. I work far from game design , but Unity taught me how to program.
In my dream Valve releases Source 2 , it's just as easy to use as Unity and then game developers have a real choice.
Or I get a spare 600k to build something in UE4. I'm a fairly experienced programer and I still can't make heads or tails of it