Black Lightning And The Future Of The CW
Aside from the argument that Arrow needs to wrap up or risk becoming a bore, there's another reason that it's time for Oliver Queen to step down - he needs to let other heroes take his place. The Arrowverse has started to grow to an unmanageable size, with five separate series over three worlds (Supergirl and Black Lightning both existing separate to the main universe, in different ways). Fans want to see more characters brought to life, more diverse heroes, more teams led by women and POC, but if none of the existing shows are canceled, the Arrowverse will become too crowded to sucessfully manage that.
The best option would be to allow series like Arrow to bow out, so that new, more original series can take its place. In the same way that Legends of Tomorrow has a rotating ensemble cast to help the team dynamics stay fresh (and allow for deaths with real impact), the Arrowverse as a whole could benefit from some rotation; older or less unusual series replaced by more novel offerings or lesser-known heroes. The existing heroes of Arrow would still have the option to pop up for cameos and the massive crossover events that fans love, but don't need to have full seasons once the core story is told.
Who Could Take Oliver Queen's Place?
Should the CW decide to kill off Arrow after season 7, there are some fantastic options for new series to take its place. One option is to create another direct spin-off with an existing character, like Black Canary (Juliana Harvaky), whose portrayal in Arrow so far has been a major disappointment to fans of the comics. Canary could also open the door to a Birds of Prey series; a female-fronted team up that could have a very different feel to Supergirl, the CW's other female-fronted super-show.
Another option would be to make good on all the Green Lantern Easter Eggs that the series has dropped over the past six seasons, and finally introduce some of the Green Lantern mythology to the Arrowverse. The Hal Jordan version of the character already has a long-standing bromance with Green Arrow in the comics, as well, which would mean a Green Lantern introduction in season 7 would be a perfect opportunity for a little comic fan-service, and would leave plenty of space for future team ups.
Of course, it seems that despite the falling ratings, Arrow is still enough of a success for the CW that they may continue to force the show to continue until it becomes utterly untenable... but we're hoping that that's not the case. As the show that launched the recent wave of superhero TV, Arrow deserves to have a proper send-off, and not a slow and painful death.
Arrow airs Thursdays on The CW