It is definitely changing behaviour, not for the better imo, the art of conversation may well be lost further down the line. I've also observed youngish children, obviously quite resigned to the fact that parents aren't switched on to them at all so just don't bother, it kind of reminds me of the learned behaviour we read about some years ago, babies in Romanian Orphanages just didn't cry because sadly it had all ready registered in their tiny minds that to do so was futile, no one came to pick them up.. It's really sad. One of my children is far worse than the other in that respect, when we had a family met up a while back his brother remarked, "he and I haven't seen each other for ages, but he's scrolling through his phone rather than talking to the rest of us" I was annoyed too we were in a restaurant at the time, I think it's rude quite honestly
I won't have it my dining room, absolutely no phones at the table.
I remember being in a garden centre when a young child absolutely fascinated by the fish in the aquarium section, for what seemed several minutes "hey mum look at these fish" over and over, she just wouldn't get her face out of her phone. The child was quite small, I wanted to say to her "he won't always have that awe and wonder, it's a brief window childhood and you're missing the best bits" but of course I didn't but that was the conversation I was having in my head 