Do not give your biometric & photos of ID's or videos of your face to these companies. Nether to third-parties. The potential failure modes here are very high risk and not worth it. Better to unsubscribe and let them know why.
I did get offered a discount in the cancelation flow, but nowhere could I have given a custom reason of my cancelation. They'll never know.
In my mind, national Id's (and the extra meta data of the person) should be public and only used for identification, not for authentication or authorization. Meaning there needs to be two or three extra steps after providing it to allow a transaction to occur. This needs to be a legal requirement for companies if they enter into contracts with a person.
If we need to prove we are not-minors or authenticate we are real or authorize access of personal information, the government should provide an api to auth the request, since they are the issuer of the document (the ID), so only they actually have the means to prove you are real and you are above 18. This can allow for a company to ask the gov, "is this person real and is this person above 18", and the gov shows me the request (otp, ussd, email, OS popup etc) to confirm the request and to select what info that company can pull. So its is 3 legged system, no third party companies involved. If the gov wants to create these constraints, they need to be the ones to provide the mean to authenticate (both for the consumer and the company). Also, when the gov shows the request to the user/citizen, it need to show exactly what the company is asking for and the full details of the company and the human representative that is making the request (almost similar to OAuth).
The problem runs much deeper than just "Whats the risk, my facepic is public already". Oh and this has nothing to do with minor and wont protect them in any way - only way to protect them is to take internet access away. The internet is not a child-friendly place and wasn't built by or for children. We should not bend to make it child friendly as it will destroy the internet in the long term.
I hate age verification as a concept and I wouldn't personally go through it to use chatgpt, but "failure modes here are very high risk" is unnecessarily alarmist.