Lucifer's been renewed for a fifth (and final) season. So, they'll have a chance to end the story the way they want, rather than leaving it on a cliffhanger when it doesn't get renewed at some point.
It's smart. They already had to save it once.
Lucifer was always slated to be a 5 year run, so they are just getting to finish it up like they always had intended to do.
I have a single word to say to that:
Supernatural.
I firmly believe Supernatural is a five season show with some really terrible fanfiction spinoff that came immediately after. Reality may say otherwise, but my version is better.
I have heard it was meant to end after season five. That the story was planned for five seasons, which is why it wraps up so neatly in that package. But that it was so successful they were sort of pushed into continuing and.......
it makes sense when viewed that way. I loved those first 5 seasons. The story was amazing. And I remember going into season 6 and just hating it so very much because compared to what came before it was utter drivel. I never finished six and in my mind, those first five seasons are all that exist of Supernatural. They were perfect.