@WestphalDenn I would say both have pros and cons. For example mate has traditional desktop and standard application menus with submenus and similar. Many #screenReader users prefer that classic style. However @GNOME is also technically fully accessible. In version 45 and 46 a lot of polishing has been made. The top bar is fully operational with the keyboard all the popup menus, dropdown buttons, toggles, sliders on the top pannel are now accessible. Gnome control center has now almost all its controls clearly labelled. The only place in the gnome control center where I expect some improvements in the future is redefining keyboard shortcuts. On my machine I have noticed memory usage has decreased after upgrading to gnome 46 so in this regard #mate desktop and @GNOME desktop are on par as well.
Also gnome is very likelly to pioneer #accessibility innovations in upcoming releases so for me the answer is clear. I'm on @GNOME since v3.4 and v3.6 days and I am not going to change that.