If you've been there 16 years, I'm sure you employer feels your impact has been worth the investment. Are you really saying that you don't feel you have made the impact you would have liked to make? Do you feel under-utilized?
That's interesting; I feel like like it's the opposite: What used to be great work is basically unfathomable today and what used to be regular productivity is seen as almost superhuman. People get almost nothing done nowadays and I've never felt like expectations were ever really at the level they ought to be at, especially with how much money people are getting.