Cannabis needs to be decriminalized for a number of reasons.
One of the most pressing reasons is that cannabis use is a victimless crime. People should not be made criminals over victimless crimes. Natural rights to grow or consume cannabis shouldn't be criminalized to the extent that innocent lives can be lost and ruined.
Families can be destroyed and communities made less safe because of the war on drugs and the police militarization that goes along with it.
There are a growing number of states so far that have moved to legalize medicinal or recreational cannabis. How does it make sense to make someone a criminal over a plant in one state, when they can freely exercise that right in another? It doesn't. And flooding the court system with these cases over victimless crimes is weakening the efficiency of the justice system to seek remedy for real victims of true violence.
there are not unlimited resources for the criminal justice system
Cages have been filled up with people who have been caught with joints, growing a few plants, or selling cannabis to those who were willingly looking to purchase it. Dealers, growers, and users etc, don't need to be caged behind bars and left as a strain on the community when they weren't harming that community to begin with. The acts invovled were consensual and don't deserve such tyrannical punishment, anytime behind bars over a plant.
Hundreds of cannabis cases are being dismissed
More people continue to educate themselves about this plant and along with that comes the growing activist movement which has been seeking to spread education and normalization of cannabis. That includes decriminalization efforts in certain regions, law enforcers saying they won't be prioritizing these cases any longer, and expunging records related to cannabis offenses etc.
Cannabis shouldn't be more of a priority than many other violent crimes which law enforcement should be focusing their time on.
Arson, theft, kidnapping, human trafficking, fraud, these also require time and attention. Regardless of how lucrative policing cannabis might be for them to pursue, it's not within the interest of liberty for all or the safety of the community.
It's also ineffective for a variety of reasons. All the while they are busy trying to police consumption habits with cannabis, people are arguably harming themselves with thousands of other socially acceptable and "legal" drugs in the market which cause just as much if not more harm that cannabis ever could.
It's time to end the stupidity, erode the stigma, and seek to decriminalize cannabis further so that less lives will be ruined over ignorance and unjust anti-cannabis bias.