We truly believe swimmers are not born, but are made. So obviously the answer is that is never too late to learn to swim!
If you got past childhood without learning how to swim, it’s very possible that you’re now stricken with fear/embarrassment at the prospect. Yes, it’s really hard to learn things as adults that for children require basically no work (like learning new languages , cycling, etc). But don’t let either of those emotions keep you from being your best self! Anyone can learn to swim, even past the age where it would have been an easily acquired skill.