Speak for yourself dude. I programmed a game engine in Java in 2011 right after I graduated college, and it powers a game that I launched on Steam in 2015. https://github.com/FourSeventy/sylver_engine

The first time i tried to make a game engine i didn't knew how to make a game engine and failed. The second time, same thing. But eventually i did manage to make a game engine. I even got to work professionally into making game engines for years. Nowadays i can make a game engine just fine.

Sure, trying to make a thing you don't know how to make will most likely end up with you not making it, but that is the case for pretty much everything.

I don't think everybody thinks they can make game engine, nor do I think nobody has ever shipped a single game in their life