I do the same, I'm healthy, I go to the gym, I bike to work, my reward is getting older fit while I see people on my age group having more and more issues.
Yup, you might be more productive than someone that is unhealthy and taking sick days, etc., at the same time you don't use your paid time off (or have days discounted from your salary, such as here in Sweden) for when you got sick.
I just don't believe in strictly direct incentives to motivate people to change behaviour, even less for a whole society. People aren't motivated just by a dangling carrot, making people healthier is much more systemic than awarding who takes care of themselves.
Maybe it's just working for an international megacorp, but I can tell you with absolute certainty they don't give a shit about my health - except to the extent it affects the bottom line. I'll get my positive recognition from my doctor because it means something from them.
Or, for that matter, "many sick days due to unsolvable chronic illness but doing their best" and "many sick days due to eating an entire bag of Doritos during lunch and feeling ill".
I got a rewards program for everywhere I eat. A miles program got every airline I fly. A tax code with a million subsidies and loopholes. Auto insurance companies who want to stick telematics in my car. Now I have health insurance companies gamifying literally what I eat and how I spend my free time.
Just fuck off already.