You said
> For friends, they need to do an age estimation only.
Thats not true. It says to share with trusted friends and 16+ they need an account in good standing (paid) and an age check, which constitues sending a face scan or id.
I literally pasted the rule directly from their site, Im surprised you dont understand it.
"Good standing" means your account wasn't moderated for violating the community standards [1] (exploiting, saying bad words, threatening users, uploading illicit content, etc).
I'm dev games on Roblox. Trust me, you're the one confused here.
[1] https://about.roblox.com/community-standards