I remember when cable TV used to be "addictive". Now I can't watch even 10 minutes of it without getting bored and pulling out my phone. Also something I learned recently: checking your phone at the movies is no longer the faux pas that it used to be.
There's definitely some hedonic treadmill type thing going on with attention and stimuli.
Please never check your phone while the film is playing. Major faux pas.
Using your phone in a cinema was, is and ever will be a massive faux pas. I have no idea at all why you think it might be otherwise.