The first step in improving a stroke is to make sure you have a grip that is conducive to the shot you want to hit. As an example, for a topspin one-handed backhand the grips most conducive are the eastern backhand and semi-western backhand grips. Does that mean that a player who uses continental can never be successful? No. Sometimes players may use a grip for a certain shot that is really not well suited for the shot and still be successful.
However, this is rare, they are the exception to the rule. As an example, of all the one-handed topspin backhands on the ATP tour I think it’s safe to say probably 100% are using either eastern backhand or semi-western backhand. So, knowing your grips and which is best suited for a particular shot is a key to your tennis success.