Tangentially, it's kind of weird how most of the sites' systems to verify your age try to get you to do it on a phone.
I've never used twitter on a phone, yet that's the only official way to go through the age verification process. Youtube too.
I attempted to get through the youtube one on a new account to see an age-gated video, but couldn't finish the process and gave up. At the time, I remember thinking it would be easier for me to buy an age verified google account from someone.
My theory is that the vast majority of users won't have an Android with root access/a jailbroken iPhone, which reduces the risk of using a virtual camera? Then they can just block emulators/rooted/jailbroken devices which increases the barrier to entry.