No. With the old style you had to draw every pixel, and you'd have to develop primitives for drawing a point, a line, or a triangle. With a GPU you essentially give the GPU a bunch of data and tell it to draw points, lines, or triangles for you. You then create "shaders" which are functions that the GPU calls to ask where to position a vertex, or what color to make a pixel, with some "magic" that passes data between the two. It's best understood by looking at the code for the almighty gradient triangle: https://webgpufundamentals.org/webgpu/lessons/webgpu-inter-s...

It's all those parts which, in the absense of GPU, would be done by CPU. No qualitative difference.