>>11911797
>>11911813

How about a game that was so delayed that it actually spanned the retro/not retro timeline?

In terms of the wider question, it depends. Technically a game like Deus Ex was developed in 2 years, but Warren Spector had been kicking the ideas around and developing story and design concepts etc. for 5 before that.

The main answer of course is complexity - people want much more polished looking graphics and stories than they used to in the mid 90s, all of which is man hours, though some Indie games beat that stereotype - particularly if they use something like Unity.