If you’re going to make a claim that strong please provide evidence.
Here is evidence for screen time being dose dependent after more than 1 hour, but it is old so none of the kids in that study had grown up with smartphones https://www.researchgate.net/publication/283687526_Dose-resp...
This is a summary article: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7012622/ you will find the dose dependt point is the first paragraph under the heading "Key Points".