A big difference is that Pokemon is still a game someone can spend hours on.
Crazy Taxi is an arcade game that's designed for quick bursts. These games were basically obliterated from retail during the PS2 era for longer experiences. They eventually found a new home on digital stores and mobile gaming but even then Crazy Taxi just doesn't seem to resonate as much as it used to.
It's a similar story for Sega Rally actually Sega Rally Saturn - 90 Sega Rally Championship 2 Dreamcast - 81 Then by the time it's on Xbox 360 Sega Rally Revo - 77 Sega Rally Online Arcade - 70
Sure some of it can be blamed on Sega not really knowing how to keep their franchises going but unfortunately for them I think a lot of it is due to their expertise being made completely irrelevant around the year 2000.