Multiple Users per Account

From the text it reads like the initial submission of age is done at "account setup". So my family PC in the living room which has 1 account called "LastName PC" shares 1 age for ever user in my house? How is this even remotely useful?

if i require my kids to use their own "kids account" 1) normal parental controls exist already so what value is added here
2) this requires, in non-linux, my CHILD to register with an online account thus tracking their data etc... which defeats the whole "protect the kids" b.s
3) as implied in the article: if this is checked against a service at creation time: requires Internet access to setup a user on a PC

Did I miss something? Like obviously this is DoA if it gets challenged by anyone who has actually used a computer in the last ... 75 years.