I always get this question. My answer is YES.
Some probably would not agree but I feel it is an essential step. You need water confidence so IMHO swimming is the way to get it.
I learned to swim before I got certified. No, it has nothing to do with certification. I learned because I think it’s cool haha. I think I took up swimming classes about a year or so before the Open Water Diver certification (OWC). It really helped.
You can’t beat mother nature but if you have the skill you won’t panic like crazy. Plus there are some “survival” skills that will be tested during OWC that might be hard if you don’t have water confidence.
Anyways, you wouldn’t want to be left out when other divers having fun swimming around during breaks between dives, would you? You in a dive suit swim with a life jacket on is so not cool! 😀