1. I rarely watch television itself (other that for the evening news, which have a dedicated tablet app anyway), but I do watch movies and other videos (mainly via plex)
2. I don't have a television and don't want one (technically I do have a 2013 Samsung smart tv, 22in full hd, but I haven't turned it on for years, it never got much use as a tv, sometimes only as a monitor).
3. I use either my 12.9 pro, or more often, my galaxy S7+ for evening news and movies (youtube is never on android, but either on the iPad pro or in my 11.6in macbook air, which resides in my kitchen and is only used for that)
4. The S7+ has slightly more screen real estate than the 12.9 (as well as better audio and video, as it's oled), but I would like a larger tablet (I know Apple is working on a 14-15in iPad pro, but it won't be before several years if ever, according to Gurman), so I'll probably pick the Tab S8 ultra (14.6in but still lighter than the M1 12.9) when it comes out.
5. I have the surface book 2 15in (but the battery in the tablet portion is too short). I also got the lightest 15.6in laptop in the world, under 1kg, which I sometimes use for movies. More rarely I use my macbook air for that.
6. I never watch a movie sitting down, I am always doing something else around the house, unless it's with friends, in which case I use a projector (incorporated into an old lenovo tablet)
For this reason, anything over 2.5 pounds is too heavy since I generally carry the tablets/laptops with one hand while carrying other things in the other hand (of course I don't watch a whole movie with a tablet in my hand, it's just for moving it from one room to the other and every room is equipped with a stand).