I would say Unreal is the biggest game engine in terms of pervasiveness. Also, isn't C# just used as a scripting language in Unity? All of the heavy lifting is dome by the C/C++ backend.
Unreal is more common than it was 5 years ago, but it's still a very distant 2nd. Probably 9/10 games released on Steam in 2021 are Unity.
You may not realize it, since the devs are slightly less bad at hiding the fact thay they're using Unity. (How did anyone at Unity ever think that disaster of a "launcher" was a good idea?)
"Garbage collection in Unreal Engine 4 is fast and efficient, and has a number of built-in features designed to minimize overhead, such as multithreaded reachability analysis to identify orphaned Objects, and unhashing code optimized to remove Actors from containers as quickly as possible."
I always feel like there are a LOT of posers in every HN/reddit discussion of GC who have tricked out gaming rigs and are desperate to max it out in every game they play, but aren't actually game developers themselves. Whilst out in the real world there is Unreal, Unity, heck even Minecraft all making mad coin using garbage collectors at their core.
HN is mostly full of FOSS and Web development culture.
Coming from the demoscene and having had a foot on game development, I am fully aware that stuff like monetizing IP and getting a game published no matter what and how, are much more relevant in the game development communities than whatever gets discussed over here.
Just look at e.g. the general opinion about Flash around here, and how it was embraced by the game development comunities.
On Reddit there are gamedevelopment forums where you will have more luck finding more real life experience.
Then there is IGDA, Gamedev, Gamasutra, Making Games, PAX, IGF and similar forums.
Fact is, not every game engine needs to be used for a Far Cry clone, and there are many ways to make money.
