For iPhones, I’ve been meaning to try out Assistive Access as a “minimalist mode”. It gives you a big icon launcher becomes a dumb phone, more or less.
https://support.apple.com/en-in/guide/assistive-access-iphon...
https://support.apple.com/en-in/guide/assistive-access-iphon...
1. You can only receive messages from numbers that are in your contact list.
2. You can only send messages and make phone calls to select numbers that are in your contact list, and which have been additionally whitelisted under Assistive Access.
3. The Settings app (which lets you configure the whitelist) is not available.