There seems to have been something that happened between the 80s and 90s and today that caused any team doing something non-trivial to go from like 3-8 people to more like 100. Like, you look at a description of exactly what the project was and you ballpark what you'd need today, and it's like 100+ people. The team that actually did it was eight humans and an office cat, and in many cases not one of them is famous for being some superhuman-level programmer.

I'm not sure what caused it. You'd think the opposite would have happened, in fact, since our tools are supposed to be so much better now. But I wouldn't dismiss the possibility that part of it's something along the lines of changing interests and work styles for developers entering the field.