Macs have "unified memory" meaning the GPU uses the same memory as the CPU and minis can have up to 64 gigs. So its a lot faster than running on a CPU and a lot cheaper than any other GPU based rig with similar memory.
It is the cheapest Mac you can get for that.
Apple is amazing at marketing to make 1990s technology sound cutting edge. I'm sure they change something for plausible deniability, as a nominalist, not even 2 of the same computers are the same.