John Wimber likens the saying of prayers to the throwing of a ball from one person to another. If you throw a ball to a friend - you throw it so that they can catch it.
If you throw the ball and the friend chooses not to catch it, or for some reason is unable to catch it, then there can be no guilt placed on you as you have tried your best to pass the ball.
If, however, you don’t throw the ball then there is no chance of that person ever catching it.
Our responsibility is to throw the ball.
When we say our prayers there is at least an opportunity that God will action those prayers, but if we don’t - how can He fulfil them.
Our responsibility is to say the prayers.