This exactly. With a little screwing around, you don’t even need a “crystal”, just a corroded piece of metal, lead corroded by sulphuric acid works well. Aside from that, you can make an earphone out of some fine wire and a small magnetic fragment, and a suitable capacitor using aluminium foil and paper or plastic film. That’s it. 3 components and some wire. Not even a battery is needed for relatively powerful AM broadcast signals. If you want to get fancy you can wrap some wire around a paper towel tube for a tuning resonator.

Or, you can just use the old wood stove in my childhood home. We had some wire racks for drying gloves and mittens supported above it, and the whole contraption played the 670khz radio station broadcasting about 15 miles away, sometimes at an annoying level of volume. You could quiet it down with some wet gloves, though.

It also would shock you when it was being loud. Somehow, the demodulated signal ended up at a pretty high voltage. I’ve often tried to imagine the circuit that was going on there between the stove, grounded at the bottom and with a 30 foot high metal chimney, the aluminium foil backed insulation in the house, the two metal pipe penetrations connected to the huge foil planes 9 feet apart on the first and second stories, the gasketed top of the stove that was somewhat insulated from the grounded base, and attached to the chimney at the top, and the corroded bolts that held the bottom to the top.