Spot on. Giving kids a smartphone and unsupervised access to algorithm driven content is child abuse, though sadly a legal form of it. Also, model the behavior you want to see, so put your own phone down around kids and let them see you pursue interests other than scrolling on a small rectangle.
If you need kids distracted for a while, at least take take the time to thoughtfully pick out some books or physical media like DVDs they can enjoy ad-free with dedicated offline media players, or give them a mechanical puzzle, or a yo-yo, or legos, or paper and crayons.