That... doesn't really hold water... historically. A bunch of other cultures practiced a Sabbath, some of them well before Moses.The Sabbath was never for the world, but only for Jews who at the time were privileged to know that God had a plan for our redemption. Once that redemption came in the form of Jesus' death and resurrection, the Law of Sabbath was no longer needed.
And a day of rest is still beneficial. 7-day work-weeks are a bad thing.
I'm not completely with you on this abrogation of the entire Law. I see where the Levitical priesthood was annulled, along with the laws and customs associated with its practice. I don't know that the 10 commandments fall into that category. God gave them BEFORE the Levitical priesthood existed...It had only reminded Israel that their work was made acceptable by concession, and not by right. The Law of Moses served to show their condemnation until Christ had issued their full pardon.
The Law of Moses is therefore no longer needed. We may need rest, but we get it each day at night, and whenever we feel we need a break.