Often people, Christians included, don't fully understand what grace actually is. Grace is not just some abstract feel good thing. It is far more than favor. It is actually God's power. Just as anointing is the external power of God, grace is the internal power of God. Grace is God's power/strength within you to help you do what is right and what God has called you to do/be. It is the power to overcome and become. It is internal fortitude.
God's grace being sufficient means that His strength at work in us will always be enough. That we've each been given a measure of grace means: God has given you exactly what you need for anything you will ever face, the "measure" needed, and that measure will be different for each one of us because we all face different challenges.
The trick is while it is always available to us, we must still tap into it and use it. We have to learn to use and flow in God's grace. That takes time and practice, just like learning to use and flow in the anointing.
So, yes, grace does do something. Amazing things actually. It is the power to turn lives around for the better and for God's glory. I've seen it first hand, time and time again.