You can’t order a mortar on alibaba, and it requires much more training to use it effectively than flying a drone.
Mortars are also large and heavy and require a crew to serve as well as spotters to direct fire which means you need to have people closer to your target and working communications.
All of this complicates the logistics considerably which makes them less effective and more dangerous to their operators.
Effective mortar attacks can be fairly easily countered in the long term by jamming radios, cutting brush and removing other natural hiding spots and by killing experienced mortar crews.
Drones can be piloted by nearly anyone and with basic consumer grade equipment they can also be piloted from anywhere in the world as long as you have an internet connection.
Mortars also have the nasty habit of drawing counter-battery fire, which occasionally leaves you short of a mortar and mortar crew. Drones are much lower risk to the operator, which is exactly why the US uses them too.
Believe it or not they do, small arms are much easier to get than heavy weapons they also are much easier to use. The cartels ironically rely on a lot of weapons coming in from the US especially as the remnants of Cold War era proxy wars in central and South America die out and they can no longer benefit from both the US and the former USSR dumping enough weaponry to invade Europe into the jungles.
Weapons don’t grow on trees, they are easy to get as long as there are conflicts in the region which are sponsored by superpowers or other patrons with sufficient resources that facilitate those shipments once those end they become rarer and rare.
Mortars are also large and heavy and require a crew to serve as well as spotters to direct fire which means you need to have people closer to your target and working communications.
All of this complicates the logistics considerably which makes them less effective and more dangerous to their operators.
Effective mortar attacks can be fairly easily countered in the long term by jamming radios, cutting brush and removing other natural hiding spots and by killing experienced mortar crews.
Drones can be piloted by nearly anyone and with basic consumer grade equipment they can also be piloted from anywhere in the world as long as you have an internet connection.