Meta Ads Strategy: One Ad Set or Multiple?

A few months ago, I thought Meta's official guideline recommended using a single ad set with multiple ads when targeting the same audience.

However, after continuously adding new ad creatives, I noticed that Meta still prefers my older creatives, even though I believe the new ones are just as good. Meta keeps directing most of the traffic to my old ads.

I’m wondering—should I try multiple ad sets, each containing only one ad? Or should I leave it as is?

If I switch to multiple ad sets, should I remove the ads one by one from the existing ad set?

Thanks!