The third and final film in the series was released in 1990 - 22 years ago.
Regardless of what you may think of the series' quality (which is subjective), it's still on the air - worldwide - in Japanese, German, Spanish, Portuguese, French and Québécois.
That's very possible, but with every changeover, they examine it's technology and make improvements. I grew up with Hanna Barbera cartoons and love their cast of characters, but I'm realistic enough to acknowledge they no longer resonate with the majority of people. Will Despicable Me last forever? I doubt it... but Universal is a park that's ever-changing, moving forward, setting the bar...