I have quite a good level of expertise about this topic for I have had the chance to work as a volunteer for the sanitation and garbage recollection industry in my home country Mexico. I would like to start saying that there is an awful lack of organization and planning to the future as well as a great lack of information from the citizens, who are the ones who ultimately litter and are the main cause of the problem.
The sanitation process starts with every household taking the trash to the closest curb at scheduled timetables, and this is where the problem starts, most people do not respect the timetables. Second people do not share a culture of recycling; they just fill up a bag with any kind of refuses, from old technology gadgets to used diapers or decomposing food. There is no culture of separating the garbage into categories.
The other big problem is that the dumping lots are all filled and the government has no specific plan to solve the situation, the only thing they do is to dig more into the ground. There is not a proper procedure neither investigation nor research to solve this problem at a near future.
Lastly, I think that society relies too much to disposable products, there is too much plastic being used and not being recycled. We should be more informed about the consequences of our actions as a society. And the government should present actions to preserve nature along with the common citizen.
Only one thing is certain, if we do not do something about the garbage problem, we will end up living in a world as the one presented is the "Wali" movie. Just as an interesting fact, did you know that the word “wali” means “helper” “protector” or “guardian” in Arabic?