Most constructions get weaker with use. But the Roman arch is an exception. The more you load the arch and the more you use it, the stronger it gets.
Holding a streak is addictive. Especially if that streak is public. If you have done something for 149 days in a row, it is far more compelling to do it on the 150th day. Like a Roman arch, it gets stronger with use.
Apps like Duolingo and Snapchat have utilized this to hook users and serve their interests. But what if those streaks could serve our interests instead? What if a daily or a weekly habit were the basis for powering through a dip and emerging victorious on the other side?