As a cinemaphile I just have to correct you
Lawrence of Arabia was filmed in Super Panavision 70, which is 70mm film without a widescreen stretch (so it's 2:1). Ben-Hur, on the other hand was MGM Camera 65 (later Ultra Panavision) a 70mm film with an anamorphic compression which lead to a ridiculous 2.75:1 (thats the image is nearly 3 times as wide as it was tall). VistaVision was a short-lived process where 35mm film was run sideways producing an image of 1.85:1, or 1.77:1 Currently proceesses are either Panavision (2.40:1), Matted (just use a portion of the frame - 1.85:1) or Super 35 (Use only half a 35mm negative but print it widescreen to 2.40:1). Panavision is a direct decendent of CinemaScope (trademarked by Fox as 'the poor man's Cinerama') - Panavision made lenses of CinemaScope, but eventually improved on them and stuck out on their own. Ultra Panavision had been retired in 1966, but was dragged back out for The Hateful Eight. The lenses proved to be so good at given a certain image, Avengers: Endgame, Infinity War and Rogue One all used Ultra Panavision (although cropped down to 2:40:1). Finally there's IMAX which in the pre-digital days was 70mm film run sideways in both filming and projecting. The grandaddy of the all was Cinerama which used 3 35mm films on a highly curved screen - obviously that was very imprecfect but anyone who has seen it will tell you nothing today even comes close. And one piece of final trivia - 70mm widescreen was attempted in the 1930s (Fox Grandeur was one) but the recent intoduction of sound plus depression but an end to it. Some early 70mm films do survive though including an early John Wayne film.
This completely useless post (lol) was brought to you by someone who studied to be a cinematographer. For a in depth look at widesceen, there's an excellent website (widescreenmuseum.com) One final bit ; TV's are 16:9 because when all common formats are added (4:3, 2:40, 1.85) it creates the least amount of black bars, although 21:9 (essentially Panavision) monitors are becoming popular.