The 90s represented a period of growing pains where the industry was scaling its budgets and team sizes very quickly and, for the most part, didn't have any pro

The 90s represented a period of growing pains where the industry was scaling its budgets and team sizes very quickly and, for the most part, didn't have any processes in place to deal with scale or to maintain a codebase for the long term - why would they, when up until that point, games usually shipped within a year or less, and the technology changed with almost every project? Today the picture is still varied, but engineering practices have generally improved - for example, daily standups are popular with many studios now, there's a corpus of books and lectures about how to architect an engine or various subsystems, etc. A lot of today's commonplace material was being put into production for the first time then, and was previously only known in some other context - research, high-end graphics and simulation, etc. In current AAA the bottlenecks mostly lie with the art and design teams. Programmers still have plenty to do, but they're also quite frequently building on old technology that has some roots in the 90s - which entails a whole different set of problems.