The Old Covenant put the burden on humans to keep the law perfectly. That was and is impossible since humans are horribly flawed and wholly incapable of "keeping the law." The New Covenant removes a heavy burden from mankind in that Christ's blood pays for our sins and iniquities. Through faith in Christ and repentance of our sins, we are forgiven and saved.
Moses said, "For I know that
after my death you will become utterly corrupt and turn aside from
THE WAY that I taught to follow [the Law]. And in the days to come evil will befall you, because you will do what is evil in the sight of the LORD, provoking him to anger
through the work of your hands.” (A temple, a gilded slaughterhouse headed by a glorified butcher.) Deuteronomy 31:29
What Jesus called "the traditions of men" is a reference to what became the Talmud, detailed instructions about how to follow the Law that was already a thousand year tradition
after the death of Moses before Jesus came. This is why horribly flawed humans are incapable of bearing the heavy burden of "keeping the Law". It is impossible to comply with the literal letter of the Law perfectly thats why its called "the burden of the Law" also because of "the death", a curse, for noncompliance. One cannot follow the literal letter of the Law without violating the deeper implications of the same exact Law.
Jesus came and taught that the Law was not to be interpreted or followed literally because the words are figurative, and the subjects hidden and it takes intelligence to decipher complicated metaphors like "eat my flesh" a direct reference to kosher Law that commands to not eat "the flesh" of swine that DO NOT RUMINATE. The creatures described whether clean or unclean represent human archetypes, their flesh is a metaphor for their teaching.
SIMPLE.
The new covenant is the same as the old, the same
WAY Moses taught to follow the Law.
This is how the burden of the Law was removed.
THE WAY that Jesus taught to understand and comply with the Laws demands is
EASY not only because no priesthood, temple, farm animals, special prayers to chant, special diets, hairdos, clothing, rituals to follow, mountains to climb, and no money required, but because it is the only
WAY to interpret and comply with the Laws demands that fulfills the promise of abundant blessings and eternal life in the sanctuary of God
on earth. The sanctuary of God cannot be made by human hands anymore than Divine providence can. The Law is the firmament, basis, of heaven.
Either you stand on the Law and enter the realm of God, Heaven, the realm of the living, or you are under the Law and remain in Gehenna, Hell, Hades, Sheol, the realm of the dead.
The only thing that became obsolete after Jesus came is the wrong way to follow the Law.
Take this manna and eat it. This is my flesh. It is pleasing to the eye, good to eat... and free.