IMO the tiling support in KDE and with gnome extensions does not look great. It cannot replace someones workflow that has been on a true tiling window manager. It is a benefit to those that have been using floating window managers for their whole life but I cannot now go back to them. Cosmic is the first desktop environment that looks like it has true tiling support (that can rival a tiling window manger) and not just drag a window to a side/area of the screen. Though I have yet to really try it out.