Funnily enough, there is no decrease in capture area with simple, very small
antennas. This is a difficult conception to get people's brains around.

There is only a (but important) decrease in efficiency because radiation
resistance decreases faster than the loss resistances incurred in matching
the antenna to the receiver. Matching loss resistance increases as the
antenna dimensions become smaller.

For example, think in terms of the Q and loss resistance of the high
inductance coil needed in an antenna tuner.