Credit card and location data is one thing. If we opened up these devices to the Wild West we’d have spyware that tracks every single thing you do on the phone in real time (and logs all your conversations and everything else). We’d also have malware that gets root access to the phone and breaks into your bank accounts.
Just by companies listed on the stock market who got that data "legally" in our current walled and "safe" garden.
I appreciate a lockdown for kids and elders, but let's not pretend our data is locked safely away in this walled garden.