Why care?

Because AI leans on that exact trick. AWS says modern GPUs are central to artificial intelligence workloads, and that you can train and deploy AI models on GPUs. When a chatbot answers you, parallel math like this is doing the lifting somewhere in a data center.

Where it came from

Games. Nvidia was the first to market the single-chip GeForce 256 GPUs in 1999. They were aimed at the gaming and CAD markets. A CPU is one patient tutor working through tasks in order; a GPU is a whole class, each kid doing the same sum on a different number at the same time.