Miz is someone who worked hard and overperformed for the expectations people had of him (so flaming out in a year). But none of that really matters. When you look back at his career nothing really sticks out. On the mic, he's a "good talker" but that doesn't mean he's a good promo. It's kind of like HHH, he can read a long script and do it for 10 minutes. In ring, he's not even fun to watch lose because he's hilariously unathletic and never looked threatening.
When he retires, he'll get a big celebration, I'm sure, and then people will immediately forget about him. Despite being there for close to 20 years, maineventing Mania, holding the IC belt a bunch of times... he's a perfect representation for that era of guys like Ziggler, Kofi and shit. The best thing they did was keep a job, but they'll be completely forgotten.