Calendars are popular, because fairly easy to trade and as said before, they constitute a logical complement to the main strategy. In practice, the negative-Theta Weirdor may close early, i.e. way before the 14-DTE target exit. A weekly calendar is thus quite handy in low IV environments, but also since weeklies are basically Theta trades, a weekly calendar can be used week after week, depending on your schedule (weeklies are quite a bit more time consuming than monthlies !).
Here below are a few free YouTube videos from Sheridan Mentoring (no affiliation whatsoever), the last one on weeklies: