Isn't macOS using the same approach? I remember it even having a warning at certain scale that it will be more computationally intensive. And blurriness from downscaling nearest bigger integer size is nowhere near as bad as blurriness from software which use xwayland and gets rendered at 1x scale and then upscaled.
https://discourse.gnome.org/t/how-fractional-scaling-works-i...
For scaling 125%, the client windows are rendered at 2x their size and sampled down. On the parent's system, a full-screen window would be rendered at 6144x3456 and scaled down to 3840x2160 (0.625%).
This gives a blurry result and is taxing on the graphics chip.
Qt apps and Firefox support scaling themselves which gives a much crisper result for fonts and line-art.