I've shown you that Hebrews chapters 8,9 and 10 show exactly what has changed between the new covenant and the old covenant.
Chapter 8 discusses how the Levitical priesthood was the mediator of the old covanent, while Christ is the mediator of the new.
Chapter 9 discusses why Christ takes the place of sacrifices and offerings and chapter 10 reiterates this and offers additional insights in that God's laws are written in the hearts of believers.
However, in all of this there is not one mention of that the holy days created and made holy by God. Not one, and especially not one that mentions that they are not to be observed.
You've already discounted, or at least refused to address, the examples of new testament Christians keeping the feast days after the death of Christ.
You've discounted Paul's clear instructions to Christians in scripture to keep the feast.
You've discounted scripture that shows that the feast days are going to be kept in the future.
You've even discounted the fact that Jesus Christ, God almighty on earth, never refuted, denied, or made unholy any of the days that HE himself made holy. He in fact observed the very same feast days he created.
Now what you've done is to take scripture and then apply your own notion that we shouldn't be celebrating the days that God calls HIS and are holy because they're celebrated differently according to the guidelines of the new covenant. It's your own notion, because as we've seen, it's completely unsupported in scripture.
And I've pointed out to you how the sacrifies, Levitical priesthood, and holy days were inseparably linked in Leviticus 23, to which you have yet to respond.
Your ersatz holy days to not meet the biblical test. They are pure human tradition. They pretend to honor God. They evidence a zeal without knowledge. They violate Deut. 12:32.