The cinematic arts requires a cinema by definition.
https://encyclopedia2.thefreedictionary.com/Transformation+o...
(or some other hit on "quantitative change leads to qualitative change")
How a film is displayed informs how the film is shot. The same would go for audio as well. How the audio is heard informs how the audio is mixed and mastered.
Not to be condescending, but it's really not hard to understand. People don't make films to be shown on a phone for instance. Or if they do make films to be shown on a phone, then it's not a film they'll be making.
Your definition would call Netflix's recent film "Bright" a show, which of course it is not. Cannes is being ridiculous.