[username90]

People didn't have the modern tools easily creating very slow programs 30 years ago, but I'd argue that it was because those tools weren't useful to them since their programs had the requirement that they need to run on machines with 10 mhz processors (with way less work done per cycle, no branch prediction etc). So most of those "productivity enhancements" comes from hardware being so fast that you no longer have to care about things.

And no, a game engine like Unreal isn't performant, it wastes a ton of ram and cpu on bookkeeping. It is a small fraction of a modern computer but back then you'd rather have all the resources instead of wasting a huge amount of them.