Not sure what Grok would care about. Except he could probably leap over things well, which would require better flexability than a person who sits on his butt all day with hams, and such shortening over time.
I think it also depends on what kinds of sports for fun you do. Dh and I like to ski. Well, he boards. And the last time we went, he was so tight he couldn't reach his bindings without a total production.
I personally feel better when I'm in better flexy condition. But once upon a time I was a dancer, and I just like to be able to move with fluidity. Keeps pain down too! However, I won't be hitting the splits mid air anytime soon.