there's basically zero actual evidence that a multi vitamin benefits you in any way. The idea was propagated decades ago. It's basically a well played marketing sham that has somehow persisted for a long, long time. Read up on the history of multi vitamins if you get the chance.
Creatine, and particularly whey protein, are very different. Whey protein really shouldn't be considered a supplement. It's food. And creatine DOES have scientific backing. It's a good product.