Besides folks being ambidextrous, lots of explanations for this.
There was the stigma is being left handed in older generations. My dad is a lefty, but does most sports right handed. Throws, bowls, shoots, all right handed. He explained to be his parents and peers led him to do things right handed. School even tried to convert him to be right handed.
One of my best friends is a lefty. He does some things left handed, like write, eat, and shoot. He will throw ball right handed, golf right handed, etc. Some of that is also availability of equipment and such.
I’m right handed and my wallet is in my right pocket. I often carry things with my left hand to as to keep my right arm free. Hand gestures, dunno, but think I do use my right hand.
Seems like folks are just trying to find things that support their theories. Somethings things just are what they are or can’t be explained by logic, especially when you’re dealing with irrational people.