So, what is the solution? There really isn't any. I do find that using film itself recycles the old cameras that would have other wise went to landfill but the rest is just a pain. I also recycle those annoying plastic containers the film comes in along with the Impossible Projects film batteries. Yes , those are 100% recyclable and they even used to have a recycle program. However, that fell through but you can still take them to anyplace that takes batteries. This to me is much better than letting it go to landfill. If you are still getting film processed like me, ask the lab what happens to the used chemicals. I have found that most labs don't just throw them down the drain. They often get collected and are sent for processing. When I worked in the darkroom in college, this remained true. We would collect all the stop and fixer to keep it out of our water systems. In most college art classes now, they have buckets in the art classes even to collect paint water, and left over paints and other materials.
When it comes to digital, I find many people more interested into the equipment itself. I often wonder where all the broken lens and last years models go. I really have no answer. I know there are some repair shops for when DSLRS break but I know more than often people would rather just get a new one since that is usually the cheaper way to go. I am not sure how much of broken DSLRS gets reused or anything like that. I am not too well versed if people do this or not with digital. I have just witnessed that people just move on to the latest gear.
I really just try to reuse the things I have and try not to consume too much. I do remember a time where I just kept buying equipment left and right but through the years I have found that you really do not need all that much to create wonderful images. I use a 50mm lens on my two 35mm and I just have one lens for my Mamyia C3. I do have my creative lens set by Mint for my Polaroid along with the tripod mount and a self timer. These things I still use often when shooting. I did recently by my compact Olympus MJU zoom that I love. I think the most important part of creating art is figuring out just exactly what you like to photograph and having your gear streamlined towards that. Otherwise you will be left with old or new cameras with lenses sitting on a shelf not being used.
Pictured above are my three favorite cameras. The ones I use the most.