The Declaration of Independence describes this list as a matter of courtesy. "a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation."
It is not a requirement, and the right to independence is not contingent upon a list of grievances.
The Secession was the political elites attempt to maintain their political power while selling it to their people as fighting for their unique way of life. Most of the South would not have noticed if the slaves had been freed and sent back to Africa.
That's not true at all. Over the course of the last few months I have discovered that 3/4ths of all US export trade with Europe was produced by the South. Virtually all of these products relied heavily on slave labor.
The North was getting very significant income off of warehousing, insuring, and shipping these Southern produced goods, and they also providing for 3/4ths of all the money to run the US Government at the time.
Yes, everyone would have noticed instantly if the economic conditions produced by slavery were stopped.
This is what that slave produced money looked like in returning imports.
New England was getting rich off of slave labor.
New England and New York got rich because of their proximity to European trading partners.