First, they don't get to interaction with other people. Because it's hard to take their eyes off smartphones. Instead of playing with friends and having family time they stay at online gaming, SNS and stuff like that.
Second,they affected by commercial objectives. Because there are a lot of advertisements on web pages, youtub and something like that. so they are impacted on marketing intention easily.
Third, they can lose their health for exmple bad eyes by small screen, less growing by electromagnetic waves.

First, they don't get to interact with other people because it's hard to take their eyes off their smartphones. Instead of playing with friends and having family time, they stay at online gaming sites, SNS, and stuff like that.  Second, they are affected by online marketing. There are numerous adverts on websites, YouTube, and other platforms. Third, they risk losing their health, for instance due to poor eyesight from a small screen or slower growth from electromagnetic waves.