Making it work in the long term is going to be a challenge. I agree.
I'm planning to implement as much tooling as possible so you can deal with annoyances that appear over time. While incentives can be outside of the app. For instance, there is an initiative called OfflineDay. https://www.reddit.com/r/OfflineDay/
And even now in-app, you can create a nudge for OfflineDay
Instead, I think it would be better to incentivize people to use their phone/social apps less.
Touch Grass. Earn Points.