"Low value content"

Heya,

Can someone please explain to me WTF "Low value content" means
in simplest english possible .. When applying for adsense ..

And also why specifically it has designated my https://yesify.me web site
as being so, because personally i think its a valuable service.

Im a bit confused about it, so If someone could explain it to me
as simple as possible, that'd be awesome!

Thanks very much,
Tom. WordPress ...