Having a "dead weight" has it's advantages - passive, no bacteria, mold, flex, resistant to shock etc. Pretty sure billion dollar companies like Siemens have thought this through and came to the conclusion that concrete is best. The negative externality of a disappointed customer seems to be larger (medium term) than the damage being done by producing the concrete.
Absolutely, I too think it's a matter of supply. So often shops refuse to take cards to avoid the fees. I suspect a systematic or law issue making card transactions more expensive.