You know if a movie is really good and I watch it for free online I usually buy it or go to the theatre with friends. Streaming movies is legal and if you get rid of it then you’ll make people go to torrents which will be harder to stop.
Microsoft and Adobe purposefully let people pirate their products. If you learn an OS or an elite program on your home pc then when you get successful and older which product will you go for? Hundreds of graphic artist teams have purchased thousands of copies of CS because the bosses learned how to use it a decade ago in high school after they illegally copied it.
What gets hurt by downloading is crappy products. The people who watch online are gatekeepers to their friends. Their friends ask or listen to the gatekeepers which wield a lot of influence so even if I watch a movie for free but if I tell a dozen or more likely thousands of people through various media and hundreds of people buy a ticket then who is harmed? Not me and not the movie company.