Less of a problem with 3D printed plastic(and other materials), as less waste. Much of the problem with plastics is over production, and not being able to recycle properly due to wide range of plastics used.
Looking at the above, one of the fun parts of the hobby, if you don't take it too seriously is including the things that bite, scream, explode etc. Wheres the fun in just having a train going round and round
Narrow gauge Francophile interested in 1m, 60cm,50cm , 40cm and smaller gauges . Build in scales from 1/6th to 1/24th. Also 1/32nd and 1/35th using 16.5mm track to represent 50cm and 60cm gauges. http://www.rue-d-etropal.com