I'm replying this for the sake of any parent who has install Microsoft Launcher on a child's phone to work with Microsoft Family parental control and can't uninstall it. I took me days to finally uninstall it because it has taken over the phone and doesn't allow you to do anything, can't uninstall, can't reset phone.
First, go to the child's microsoft account to remove the device, then you log into your own account and find the list of devices under your child's name and unlink it. Then you go to your child's phone and go to microsoft launcher and sign out from your child's account. Then you sign in with your own account and then now the uninstall option is available! (I'm not sure if you had to sign in without own account to uninstall, but I did, just in case...)
Microsoft Launcher's parental control doesn't allow you to use Google Chrome but it is required for educational purpose for school. This app is a nasty one, so think thrice before installing on a child's phone.