Hams have privileges on 2200m, too! At those wavelengths people are using big loading coils. Saw a video last week of a guy in Alaska with a sizeable loop in the trees and was putting in about 1 KW to get 1W EIRP.

WSPR is all over the ham bands. There's people making relatively small, hydrogen filled balloons and trying to see how long they will stay alive. They're using WSPR on 20M to broadcast their telemetry (search for Traquito).

Wikipedia is just being weird by using an MF band in its example. Most WSPR is in the shortwave bands, which can use large antennas, but not THAT large.