I was wondering their reasoning, here:

We have publicly supported mandatory age verification of viewers of adult content for years, but any method of age verification must preserve user privacy and safety.

Basically, they don't disagree with mandatory verification, they just wish for it to do so in a way that doesn't violate the privacy of adults legitimately accessing the content.

Their suggestion for this is:

The only solution that makes the internet safer, preserves user privacy, and stands to prevent children from accessing age inappropriate content is performing age verification at the device level.

Essentially, do age verification on-device, and have the device send the okay to view signal to the site. This is something websites cannot implement on their own, until device/os developers implement such. I agree this is a good solution, but I think it'll be difficult to push tech companies to do this without further legislation.

I think it might be good to seek the EU to require tech companies to implement such a on-device feature, which will naturally roll out to all tech devices.

Edit: these quotes are from the porn company, not the court.