My sub 10 years old kid has a smartphone, but it has no sim card and runs a Google child account, so nothing can be installed without me approving, and it only

My sub 10 years old kid has a smartphone, but it has no sim card and runs a Google child account, so nothing can be installed without me approving, and it only knows about the home wi-fi. We also control how much it is used and it is not left in the bedroom at night. Previously it was actually locked into kiosk mode with Spotify Kids being the only accessible app. Great way to use an old phone. It even has a broken screen but we've now had 3 years extra use (Galaxy S7).