Any age verification should come with an OAUTH style government run API. The idea being you verify your ID with the government, and the service that required age verification gets back a true or false for does this user meet this age requirement. That way the amount of data shared is kept to a minimum. The UK, and Brazil who passed a similar law, 'cheated' by just forcing private companies to figure it out.
Honestly I'd rather have private companies figure it out. Then at least you'll get multiple options, including from privacy-first companies. But that still sucks, and my preference strongly goes towards OS-level Age Indication. Just as effective in practice, 100% private and offline.