I have always found that most Christians (both Catholic and Protestant) really miss the point. This was a repurposing of Passover and a direct fulfillment of the prophesy of the Passover. He had clearly become the Passover lamb, inspected and found without blemish, and meeting all the other rules.
The point isn’t that the symbolic cup and bread become His body and blood. This was a directive to continue with Passover with the celebration of this fulfillment.
Christian leaders miss the point when they celebrated this weekly or monthly. This is one of the 7 appointed feasts. (One could argue it is the first 3 rolled together.)
Why do Christians not celebrate all of the feasts as directed? Sadly, most Christians never learn of them in churches.
Galatians 4:9 But now, after that ye have known God, or rather are known of God, how turn ye again to the weak and beggarly elements, whereunto ye desire again to be in bondage? 10 Ye observe days, and months, and times, and years.
The new covenant