Radials function as a counterpoise, and, when there are enough radials, a
ground plane.

If you wish to attenuate ground losses, then it is best to make the most of the
surface by using as many radials as possible. The first dozen+ are the most
critical in reducing ground losses. Even a dozen or so helps substantially or
over 3, for example. Several dozen reduces ground losses substantially.

Elevating radials always helps.

73,
Chip N1IR