I once worked at McDonalds. New owners tore down the building and rebuilt it. We not only had new kinds of equipment, but a whole set of new rules as to how we prepare the food. Things ran much smoother, it was a better way. In the old way, as manager, I had to guess what the customers would order and make those kinds of sandwiches ahead of time so that they would be ready upon order, and our drive thru would run faster than making it at the moment it is ordered. The problem with this is if the customer asked for no mustard on their burger, or did not order the premade sandwiches, we had to throw away these premade sandwiches when the timer declared them too old to sell. That was behind the scenes, but to the customer they got the exact same sandwich as in the old building, but it was fresher because it was now made to order.
In the same way, Christ tore down the old and rebuilt the new in three days. The exact same product is still produced, just in a different way. Under Moses it was done physically, but under Christ it is done spiritually. So, for example, take the old law not to murder physically, under Christ if you hate your brother then you are guilty or murder spiritually- whether you carry it out physically or not. So the same product is produced- do not murder, do not even hate to begin with. Jesus says if you love God and love your neighbor you will not murder, steal from your neighbor, or etc, and as a result we obey God just the same as those who were under the law of the prophets- same product/result, but different method/authority.
So what is the difference? There's a HUGE difference! The bible says if you obey part of a law you must obey all of it! Therefore, if you obey any part of the old law, you must do all of it such as stoning people, making payments with animals, and good luck finding a two thousand year old high priest to sacrifice for your sins on your behalf.
So, you see, if you read the scriptures I first posted, you will see that it is not flawed, but made perfect, because under Christ we are free from the old law that was not perfect. (Hebrews 10:4 and Hebrews 7:19 but Colossians 2:14).
Show me where Christ tore down the Law and rebuilt it.