Capsules are considered more advanced drug packaging because none of the drug dissolves in your mouth when you swallow capsules. Unlike pills, 100% of the drug goes straight to your stomach, so there’s no variation in the drug dosage, and the patient won’t complain if the drug is bitter.
Also because you can open the capsule and pour it into the glass of water, if you have trouble swallowing pills. Which defeats the first advantage, and you can simply order powdered drug instead of pills, but it won’t come pre-packaged as pills so it will be more expensive.
None of that matters for vitamins, you generally need more than 1000% of the daily dose for it to become harmful, so each pill contains more than your body really needs, because there are no side effects, so you can buy a pill and lick it, chew it, crush it, and add it to your coffee, and it will still work just fine.