Facebook users are inundated with so much content every day, sometimes they just want someone else to make the decision for them. Creating a curated selection of products takes some of the work off your audience and simplifies their decision making process. Using Collection ad helps you group similar products together into an immersive in-app experience that includes ways to browse and learn more.
While carousel and collection ads are the obvious choice for these kinds of situations, a dynamic product ad or Instant Experience ad can also work well. Regardless, when featuring a set of products, make sure that each one is visually distinct from the other and includes its own headline and CTA (which should be specific to the individual product).