The tithe was used to support the priesthood. We no longer have a priesthood that depends on tithes and animals presented to them for sacrifice.

We're rich by the standards of this world. You could make the case that we should be giving much more than 10% of our income to God.

(2 Corinthians 9:7 NIV) Each man should give what he has decided in his heart to give, not reluctantly or under compulsion, for God loves a cheerful giver.