Ubuntu especially are now focusing on blingy desktops that somehow require really new cards and hardware only, and yet are also trying to throw away the traditional desktop to cram themselves onto a phone.
Bling is so much less work than games that even a low-end GPU can drive Unity's bling. The only problem is when you have no working 3D driver at all.
Phones actually have better 3D drivers than desktop PCs, because Linux is the dominant kernel for phones. Every phone SoC has working GLES 2.0 Linux drivers. (The drivers are proprietary but that doesn't bother Ubuntu.)
Bling is so much less work than games that even a low-end GPU can drive Unity's bling. The only problem is when you have no working 3D driver at all.
Phones actually have better 3D drivers than desktop PCs, because Linux is the dominant kernel for phones. Every phone SoC has working GLES 2.0 Linux drivers. (The drivers are proprietary but that doesn't bother Ubuntu.)