To be fair, 101 of those in your 1st group were made between 1966 & 1974, 8 years of the 1st generation. The other 615 were made between 1987 & 2004, 17 years of the 2nd generation. (Piggybacking on the 8 years of success of the TOS film franchise)
However, to compare 5 year stretches between the 2nd & 3rd gens... between January 1993 to December 1997 Star Trek released 255 episodes with 3 different shows, actually airing on television in syndication, & not just a single company's content streaming service, & were also into production on the 3rd TNG theatrical film. That imho was as much or more of a content boom & commercial blitz as this current 5 year stretch has been