It's a fine line for me. I have a 5yr old.
Phone, tablet, laptop.
We do no screen days 3days a week. We only do 3 because I also don't want to hold him back from using tech to his advantage later on and not be able to use it as his peers can.
As to what he's watching, I use YouTube kids, but I have strict limitations set so only channels I approve can be watched.