More confederate monuments were built in 1999 than in 1869. The year with the most confederate monuments built was 1911, 46 years after the end of the war. That’s like as if there were now a sudden spree of building Vietnam War monuments everywhere.
Confederate monuments were overwhelmingly built during the Jim Crow era. The Daughters of the Confederacy built most of them as part of their revisionist lost cause project, trying to write slavery out of the war. Then there was also a lot of them built during the civil rights era, to send a message to civil rights activists.
Sure, it’s worth saving a few of them to put into places like the Jim Crow Museum of Racist Memorabilia, the National Civil Rights Museum, America’s Black Holocaust Museum, or the National Civil War Museum. But there’s many more monuments than appropriate museums for them. Getting rid of the least historically s significant ones isn’t a big issue.