It’s called a hyperbolic arch, it’s used in things like bridges and roofs.The mortar doesn’t do the work, the arch does. I’ve even seen designs without mortar simply because the trick is in the arch.I don't know why there are so any people correcting the video. This is made by AI, there's someone somewhere churning these out and couldn't possibly care less about the accuracy or quality of the videos. You are just ad revenue to them.