Chromatic aberration may be a contributing factor, but I am surprised the author didn’t mention that S cones (which we use to perceive blue) are only 2% of the cones in the retina [1]. Additionally S cones are distributed randomly when compared the regular lattice of M and L cones. The distribution of the different cone types alone may be sufficient to explain why our acuity for blues is impoverished relative to reds and greens.
This lower resolution of blue is pretty well known in recent image compression work (XYB space of JPEG-XL and guetzil), and number of S cones is the only explanation I have seen on that.
[1] https://en.m.wikipedia.org/wiki/Cone_cell