I never run more than 6 days per week, so I have no streak to speak of and I'm not interested in pursuing one. However, since the surest route to success is consistent, steady effort, keeping a streak going is probably better than what 90% of hobbyist runners do. It may not be the optimal choice every day, and a lot depends on what kind of running they actually do, but streak runners have identified something important and are doing it mostly right.