Nearby antenna elements do affect each other. Consider a Yagi-Uda. Pointed in the "wrong" direction, the director and reflector elements will reduce the EM power that the driven element receives from the impinging RF field.
However, a parasitic loop can often increase the power to a nearby small radio antenna, rather than steal (or "zap") power.
The magnetic field concentration caused by a multi-turn loop inductance, whether with a ferrite core or not, concentrates the EM field lines not only inside the loops of the coil, but in the total virtual aperture area or volume nearby. All nearby EM field lines (in the entire neighborhood) will be distorted towards the loop inductor and/or volume of higher relative permeability.
There are inductor coil antenna products that take advantage of this. You merely put a tuned passive loop antenna near your small receiver's internal antenna to increase the received signal level. Here's an example of one by Kaito, a "Tunable Passive AM Radio Loop Antenna", but there are other vendors of similar products:
If you are wondering where the "added" power comes from, consider it stolen, not from nearby receive antennas, but from the transmitter's antenna, due to more efficient inductive coupling between the two stations. All the EM field lines will be pulled closer, not just the ones near the receive antenna ferrite core.