A lot less fuel is used with a slide on camper compared to towing a camper trailer.
Less track damage is likely on unmade tracks compared to a vehicle towing a trailer.
The shower and sink. Because the shower is at tray top height it is easy to collect the soapy water either in a bucket or in an under tray grey water tank for disposal well away from water courses and other sensitive areas. The same applies to sink water.
The toilet. This is a big problem at some camp sites. Black water processed with environmentally friendly products can significantly reduce this environmental impact.
Landfill of products at the end of their useful life cycle is a major problem. This product is substantially constructed of aluminium and is highly recyclable.
You can do many other things to reduce environmental impacts. Why not get an under-tray storage box to keep your rubbish in until a suitable place is available? Utes work well for this. It keeps the rubbish together and well away from everything else. If you took it in then take it out - leave nothing behind.