Don't let perfect be the enemy of good.
Not only that, but having this locked behind something that works for 95% of users means the other 5% will never have enough leverage for any other implementations to be approved. Which is absolutely unacceptable for such an essential feature like age verification.
The target, which are the children who access "forbidden" websites without authorization is likely to be lower than amount of people who won't be able to access due to those narrow specs.
This is a general computing crisis.
The EU wallet does use an open standard, and the wallet app itself is developed in public as open source.