Giving is a great thing. It's beneficial to others. That's what giving does. It benefits others.
If you want to give away 10% of your income, then fly and be free and do so happily. Just don't expect that God will bless you more because you give 10%. Again, giving is for the benefit of others. If you surveyed all the needs of others around you, you would easily give up 100% of your income to meet only a tiny amount of the needs around you. What's left then, is that you are free to decide in your own heart if you want to give 0%, 2%, 10%, 30% or any other amount. It doesn't even have to be based on a percentage. You simply know how much you've got and you see the needs around you and you freely decide how you want to give for the benefit of others.