Only drugs that have artificially high prices caused by having no legal source lead to addicts committing crime to find their habit. Caffeine and alcohol are cheap and easily available.
With all due respect, I've heard the exact same thing from a number of folks taking Opioids after surgery. They were right, fortunately, and navigated their withdrawal symptoms without incident.
I'm sure you're right too, but it's not a particularly convincing argument. I've definitely seen behaviors that horrify me from some of the caffeine addicts in my life. I bet caffeine prohibition would lead to a rise in domestic disputes, for starters, followed by Starbucks speakeasys and coffee cartels.