Well no, that's reductive, Slavery was used by the North as its later justification, but it was due to many different reasons, not just slavery.
For instance, voting and electoral politics were highly controversial flashpoints that directly catalyzed the Civil War.
Beyond the moral debate over slavery itself, the breakdown of the democratic process and deep structural imbalances in the voting system convinced both sides that the political process was failing.
The fundamental breakdown of the American voting system was driven by population shifts, political corruption, and the structural design of the U.S. Constitution.
In the 1850s, the federal government tried to solve the expansion crisis by introducing popular sovereignty, allowing voters in new territories to vote on whether to permit slavery.
This triggered a violent collapse of the democratic process in Kansas.
In ten Southern states, Abraham Lincoln was so unpopular that his name was not even placed on the ballot.
Because of the rapidly growing population in the industrial North, Lincoln won the presidency through the Electoral College without winning a single Southern state.
Southern leaders realized that the North possessed a permanent voting majority.
They believed that no matter how the South voted in the future, they would remain politically powerless at the federal level.
During the elections to determine the future of the Kansas territory, thousands of armed residents from neighboring Missouri crossed the border illegally to cast fraudulent ballots.
Because the voting process was so heavily rigged by fraud and intimidation, opposing factions boycotted elections, set up their own rival legislatures, and then drafted conflicting constitutions.
The total collapse of election integrity directly degenerated into the guerrilla warfare known as "Bleeding Kansas."
By 1860, the national political parties that previously held the Union together completely collapsed.
The Democratic Party fractured into Northern and Southern factions, while the Whig party dissolved entirely, replaced by the purely regional, Northern Republican Party, without cross-regional political alliances, voting became a strict "us versus them" regional battleground.
While Slavery was a major, economic and political focal point, it was not the main reason the Civil war occurred in reality, it was one of the primary causes, but was used as the backdrop of other underlying issues.
The Civil War was about Slavery, but it was also about the electoral process, state rights, disenfranchisement, economic issues and more.
One of the primary reasons Tim Pool for instance says that civil war is brewing, is because of the parallels that the political landscape of today shares with that era.
Widespread voter fraud, rigged elections, no faith in the electoral system, a modern implementation of the 3/5th compromise where illegals are used to inflate the voting power of Democrat states and number of seats, the same way they used the aforementioned political compromise to artificially inflate their voting power in that era.
I didn't see the original post, but I do have my own opinions on the Civil War, the main issue many have when talking about it is they have a visceral reaction to the subject, they can't talk objectively on it, and that may be due to racism, which I doubt, or it may be due to them having family who fought on both sides, who don't adhere to the modern narrative of "it was just about slavery," that is so popular.
