I think in our modern age, a lot of people can be surprised at just how fast the CPU is relative to GPU. Slower, yes, but compiled SIMD-enabled CPU code is bloody fast. I've seen people on HN claiming "just put it on the GPU and be 10,000x faster"; I can only assume this comes from comparing interpreted Python code with compiled kernel code or something! Basic drawing code is highly likely to be memory-bandwidth-bound; Some napkin math shows e.g. a 4070 has about a 10x performance advantage over a Zen4 CPU (500gb/s vs 50).

Rant out of the way, obviously 10x faster is still an order of magnitude faster! I've continued to be curious if there's a way to properly batch geometry in the QT backend to remove all the state-changes that the QT painter is doing that kill performance; a powerfully GPU-accelerated backend for widget based apps would be incredibly useful, although given the dominance of web/electron apps these days not a useful feature for a commercial company to build.