Which Camera Brands Still Sell Batteries for Older Gear?

CineD went brand by brand through Canon, Sony, Fujifilm, Panasonic, DJI, Insta360, Blackmagic Design, and GoPro to document battery compatibility across current and recent lineups. Canon comes out well, still selling new batteries for bodies going back to 2008. Insta360 is the cautionary tale: the Vertical Battery Base for the ONE RS 1-Inch 360 Edition is already scarce on the used market, and the camera is only a few years old.