The show should have ended in season 10.
right hear me out on this if you rewatch the show all the way up till season 10 specifically episode 5 you realise that was the perfect place to end the show the episode ends with casey leaving to look after the darden boys and hes dating brett severide and kidd are married earlier in that episode cruz has his kid the frequent flier ambulance is setup and being used and chief boden has left 51 i just think personally instead of trying to drag thr show further on new characters trying too tie things together badly they should have just built it up to this point where not everything was perfect but the main storylines at the time where wrapped up it was a perfect place to stop in my opinion
i just dont understand why they decided too continue the show beyond this point