The first phablets were probably the Galaxy Note line starting in 2011 which was met with some skepticism due to the size of them. These were well before the edge to edge screen days. So you had 5.7 inch screens with a bezel.
They were huge but I would routinely see small women pull these things out of their hand bags and press a device that obscured almost their whole face and start chatting.
Things steadily got bigger from there. The general population WANTED this.