Its less so that it is or isn't simple.

A lot of this stuff actually is fairly straightforward.

It is moreso that a lot of people are sophomoric idiots, wise fools, people who don't realize that they are just around the peak of Mt Dunning Kruger, people who do not realize the extent of what they do not know, what can go wrong.

Either that, or their boss/manager is there.

A lot of these things are obvious and well known to people with moderate levels of actual technical experience... where they actually pop up and become relevant.

Buuuuttttt... not everybody actually experiences, in significant detail, that kind of problem actually popping up, depending on exactly what that prior experience is. Also, the nature of many many game studios is that those people with moderate or more experience are basically treated as contractors and shuffled around, and as a result of this, they just do malicious compliance, they do exactly what they are told.

Because either the managers are egomaniacs, unwilling or unable to actually listen to good advice... and/or the entire team generally develops a toxic positive hugbox culture, that hand waves away valid and legit problems, and calls you an asshole for being persistent about bringing them up.

You can infact raytrace your way into reliable and robust and efficient visibility culling that even works with servers/multiplayer environment. Many succesful games and engines do exactly that.

Its just that you have to be quite clever and nail this down pretty early on in the dev cycle, otherwise, technical debt and timeline problems compound geometrically.

And, what make line on stock market go up != what make line fly around smart and clever in video game.