Isn't this survivorship bias? How many were successful in contrast that just used an off the shelf engine?

Regarding Source, Unreal, etc, that was back in the day when making an engine was much easier than today, due to lower player and graphics demands, which they then iterated on.

> that was back in the day when making an engine was much easier than today

I don't know specifically about how creating game engines was back in the day with lower level languages, but I can hardly imagine it was easier than today. I don't know of many things that are harder today than ~30 years ago when I first touched a computer, everything seemingly is getting easier and easier. Especially creating games, and for sure creating game engines. I'm not complaining, I'm loving the Cambrian explosion of games and especially indie games, but I do think we're seeing more and more games and game engines being made because it is easier today, not harder.

> How many were successful in contrast that just used an off the shelf engine?

Yeah there's successful games that used an off the shelf engine but saying very few roll there own is plainly wrong when a bunch have. And that's without mentioning the whole flash era...