Last month I was attempting a game in Unreal Engine for fun. The article does a decent job describing some of the problems. I know C++ and use C++17 at my job, so it wasn't an issue. One minor point is that Unity just tends to work. Unreal engine has some odd bugs some times and the lack of community I think is a huge downside. I have made a few games in Unity and it is a lot easier to find help and free support.
Unreal has a better rendering system in my experience, and although this mostly matters for realism, it can also be very valuable in other situations.