Pediatricians I know can basically immediately tell the difference between a kid raised by the TV/phone and one primarily read/spoken to. Obvious differences in verbal ability.
I like to think my kids enjoy devices and digital stimuli in moderations, and do try to read to them often, but I wish there was a decent way of checking their development.
They’ve been a thing for 8-10 years, and the window for kids to be influenced this way is only a couple of years, so we’ve had several cohorts of kids grow from 1-4 in the smartphone era.