Smartphones
My generation and older remember before smartphones became prolific and realize on some level that something is a bit off, a bit weird. Those who've grown up only knowing smartphones and the constant connectivity they provide believe this is just a normal part of modern life.
It's not normal and it's not healthy. Americans spent over 10 hours with screens per day. Excessive smartphone usage has been linked to neck and back issues as well as to sleep deprivation. Studies have linked elevated screen use to higher levels of depression in both adults and children. One study found that simply having a phone nearby(even without checking it), can interfere with attempts at interpersonal connections.
This is beyond weird. Something's wrong. Left unchecked, constant screentime can lead to mental, physical, and interpersonal dysfunction.