Obviously He is saying that the former covenant was inferior in some way.
The fault wasn't in the covenant itself, it was with the people with whom the covenant was made. So the new covenant was based on better promises. What was that better promise? Back to Hebrews...
KJV Hebrews 8
10 For this is the covenant that I will make with the house of Israel after those days, saith the Lord;
I will put my laws into their mind,
and write them in their hearts: and
I will be to them a God, and they shall be to me a people:
The first covenant was broken through disobedience by Israel. As hard as they tried, they failed. Good sent prophets and even His own Son, but Israel killed them all. They wanted to do things their own way. The sacrifices and temple services had become a ritualistic meaningless facade to cover gross hypocrisy and apostasy. But
God's promises are sure, even though ours are like ropes of sand. Casting aside the poor ineffectual promises of man, God instituted a new covenant that excluded completely man's works, and made it clear that obedience is not only possible through His strength, for without Him nothing is impossible, and without Him we can do nothing, but also that obedience to His commandments does still affect our ultimate destiny, as Revelation is abundantly clear that those who do not obey His commandments are outside the gates of the kingdom.