Why would anyone go out, buy a new Radeon, install it in their computers (assuming there is room, which in ML cases is not always true), and reconfigure any drivers and all the other hassle, just to use a window manager? That's assuming such a thing is even possible (e.g. work restrictions).
Because they “would love to move from i3 to sway”? The cheapest passive Radeon is less than $50 on Newegg and I’m sure a lot cheaper second-hand, and $50 doesn’t seem like much to spend on something one would love to do.