When they write "GitHub", I guess they mean "Microsoft"? Maybe this is the hero we deserve, but it's not the hero we need.

Can someone please ELI5?

Go and play outside.

Maybe age assurance should be in the display. The display's camera has to verify the age of the viewer to display adult content.

That might be simpler. Estimating age with a camera is already common in China. Cameras are cheap, and displays now probably have enough processing power to do it locally.

Will work for TVs, too.

Kids have already found that drawing a false mustache on themself works to defeat age checks using a camera.