Why does it take movies 1-3 years to make while TV shows have are able to have a new season every year?

Why does it take so much longer to make movies compared to tv shows? Movies are 90-180 minutes while tv seasons can be at least 10 hours long. Is tv production simply much more stressful and expedient or is there some underlying cause here? I remember the show Lost used to have 24 hour long episodes, so about 18 hours worth of screen time. Some movies, like the planet of the apes take 3 years between each movie. Yet there are some that came out one year after the other, like pirates of the Caribbean 2 and 3 and the matrix sequels. Thanks for any help for this via /r/movies http://ift.tt/2v7LpqZ