EDIT: Also note that there is nothing new with the Neo here, as all Macs since the M1 have used the same chip architecture as the iPhone.
Desktop GPU designs did not focus on tiny efficiency gains, and often only has a primary plane, a single overlay plane (for e.g., a video), and a dedicated cursor plane. Some even have to share a single overlay plane between all connected displays. It's a recent thing for desktop GPUs to get more flexible in this area, in part to improve laptop battery life in the cases where the laptop is almost entirely idle.
(For those unaware, a "plane" here is the entity in the display controller you configure to show a rendered graphics buffer, in a particular location and with particular transforms. You commonly have one plane that just covers the whole screen, and then sometimes put dynamic content on top in other planes so you can avoid having to redraw the main buffer when smaller bits of it change, like a video player or cursor. You could also e.g., scroll by rendering an entire document in advance and then move the plane around to reveal parts of it.)
