Page "Point particle" Paragraph 16

Nevertheless, there is good reason that an elementary particle is often called a point particle.

Even if an elementary particle has a delocalized wavepacket, the wavepacket is in fact a quantum superposition of quantum states wherein the particle is exactly localized.

This is not true for a composite particle, which can never be represented as a superposition of exactly-localized quantum states.

It is in this sense that physicists can discuss the intrinsic " size " of a particle: The size of its internal structure, not the size of its wavepacket.

The " size " of an elementary particle, in this sense, is exactly zero.