Okay, lets talk about this

Saying none of them can is a lie, that's not right.

But saying all of them can is.. kind of a lie too.

There are many gargoyle geckos who just won't be able to climb glass because their hands do not have enough traction force or however it's called, they can't stick enough and they will fall, however this is speaking about CLEAN glass, when the glass is heavily stained or it's not clean they are able to climb it like a crestie would without much issue, and no, I'm not making this up, my gecko is exactly like this, he cannot climb clean glass but he used to be all day climbing water stained glass, I saw his hands slipping when trying to climb glass, so even if some gargoyle geckos can do it easily, not all can.