Why noy use a truck.
Not as effective or efficient.
They seem to be the most effective.
Trucks? In specific situations.
You need enough momentum. The target to be in the street. Once you hit them you can't be sure you've killed them. Unless they're plowing into a crowd you're not going to hit many people. It's hard to fit a truck into a school. Someone yelling, "watch out!" is enough to mess up the hit. Trucks are easy to dodge.
Man with a rifle vs man with a truck, my money is on the man with the rifle.
you can load them with fertilizer if you really want a mass-casualty event.
Explosives are fine when you want massive casualties and don't care who is hurt. But it takes a lot more preparation than walking into a church with an assault rifle.
We can't have healthcare or decent public transport, like most the industrialized world because our absolute reliance on oil, and now coal.
Find me the middle.