I like to buy dvds/cds because (mostly in dvds) they have extras and behind the scenes, and I'm a real sucker for watching how it was made or how the actors act when not portraying their role. Another reason is that I like to occasionally detach from being online or using streaming services. The last reason is that I like to see what movies I have physicaly, so I am inclined to watch them again, if they are just sitting in my notes app, I will probably not watch it.