I believe it's much more in their interest to buy old TV shows. A good movie will keep you occupied for what, two hours? Seinfeld: almost 19 days of watch time. Friends: over 5 days. Community was barely ever popular before Netflix bought it, now there's plenty of people that enjoyed it for 2 days and 7 hours of watch time (its subreddit went from 266k on April 2020 to 482k right now).
I believe it's also in their interest to spread out stories that are realistically one-movie-long into 5-6 slightly drawn out 40-50 min episodes.
I just wish they fucking stick to them instead of cancelling them after like two seasons. Orange Is The New Black is the only original of theirs I know of that goes above two days of airtime.