[guidedlight]

The issue is that if you don’t prove your age, access is blocked.

So it’s not optional. At least in Australia.

[defrost]

It's entirely optional within Australia - I don't use Apple, nor do my kids or their kids.

[guidedlight]

If a website/app requests you to prove your age, you can’t optionally avoid it and continue to use the website/app.

[defrost]

Hasn't happened in any meaningful way yet, so I'll deal with that if and when it happens.