Crash always seemed like "this would be a really fun rental" type of series. I remember getting the third game in the series as a present, and I remember getting really bored by the middle or last 1/3 of the game. I had more fun with the Bugs Bunny time travelling platformer than Crash 3.
Platformers are one of the easiest genres to grow out of. Classic 2D Mario was never about collecting shit, it was about speed and doing shit right based on memory and skill. When collecting shit became the focal point for platformers, specifically the 3D era of platforming, its easy to check out and never want to play another one ever again.
That's why Conker's Bad Fur Day is still a classic, its a linear game with puzzles, point A to B platforming, and action. There was very little fluff.