No, they need to quit while they are ahead - Just look at the Bourne franchise, you had 3 great movies and a sold Trilogy, not an easy achievement. Then you had a decent movie in bourne legacy, IF if hadn't been labelled as Bourne, and a unnecessary official follow up in Jason Bourne which was dire due to how utterly unnecessary it was.
John Wick has been excellent so far, however by the end of John Wick two it was starting to feel a bit repetitive and (in my mind) in dire need of a 'conclusion'.
Now yes you could argue that given the nature of the protagonist's 'job' or expertise, there will always be another Mark, or another up and coming hitman/woman looking to prove themselves by taking on the best of the best, but for me stopping at the right point and leaving an audience wanting more is a difficult skill and something you don't see much of these days. Given how refreshing JW has been, it would be cool if they just stopped at JW III and left the world with a fantastic modern revenge troilgy fans can enjoy for years to come, without taking to talk about JW 4, the movie no body really needed but was done, because reasons.
Don't get me wrong, I am really happy we are getting what I hope will be the final movie and culmination of 1&2, but for it to go 4,5 6 movies - No, just no.
These are some of the best, straight-up action movies in recent years, and the world building and character development with the supporting cast and the Continental and everything else just elevates it.
DD and JJ) and pretend it doesn't exist hah! 
I agree. I will be keeping an eye on the TV show's development and I suppose the first trailer is going to give a good indication of what to expect.
