Something like a simple markdown renderer has little reason to use the GPU. But a terminal emulator has absolutely no reason to use one. The bottlenecks there are system I/O and legacy API's, not the rendering performance.
The terminal statement is false. In fact I contributed an Alacritty feature that stopped rendering when the window was occluded that cut CPU usage from ~10% to ~0.4% when not visible. There's also a misconception on what GPU's are useful for. Being the graphics processing unit they are much faster for processing images and glyph graphics then the cpu.