It is claimed that the electron has a size less than $10^{-19}$m. I presume this is based on high-energy scattering experiments.
But isn’t this apparent size simply a function of the high energy of the particle used to perform the scattering experiment?
As the target electron is scattered it will have a lot of uncertainty in its momentum and therefore will be well localized. But this length scale has nothing to do with the intrinsic size of a target electron at rest.