Too much close up screen time does damage their eyes.
Most parents don't keep a lid on it and let their dc spend hours and hours watching videos or playing online games.
It is addictive and must ultimately impact their brain development. Give it a decade and we'll know that too much screen time at a young age (but even if older) is as damaging as inhaling second hand smoke or letting your dc eat artificial sweets and drink sugary or carbonated drinks all day long with no restrictions.
Mine also get screen time, too much of it. I saw a very young baby at the supermarket maybe about 10 months old sitting in the trolley holding a phone watching a programme.
I think it's really hard for parents who are busy with work and managing family life in a pandemic to limit screen time as it gives them a break even if they know it's the right thing to do. Parents are addicted to their phones and devices as well, so it's no surprise kids are too.
Almost everything we do now is digital. WFH online all day, shop online, watch streaming programmes rather than walk to the video store and choose DVDs.
In another 5-10 years whatever analogue life is left now will have moved online too, I don't think we'll be visiting the GP and I wouldn't be entirely surprised if online schools would become a thing.
Facebook are working on it, watch out for Meta. Interesting times we live in.