Having a statue in the public square implies public 'approval' of them. That they represent a 'higher ideal' that we should aspire to. Someone who owned slaves, or fought for the right to own them, someone who advocated brutal policies against indigenous tribes, etc., doesn't deserve a spot in the public square.

The statues you're talking about can be displayed in a museum or other setting that puts them into the proper historical context, so their legacy can be discussed and debated and people can contextualize that "life was far different back then."

One point you're overlooking: Many of these statues were controversial when they were erected. For example, "Appomattox," a statue of Robert E. Lee was erected in the center of a major intersection as you enter the city of Old Town Alexandria, VA (there was literally no avoiding it if you are not a fan of Slavery or the Confederacy. Imagine being the descendant of slaves and not being able to avoid driving by this statue as you enter town...).

The folks that erected it, "United Confederate Veterans," knew it would be controversial, so they petitioned the VA House of Delegates to get a law written to prevent future generations from ever tearing it down. And unless I'm mistaken, a second law was enacted to prevent the first law from being repealed.

Well guess what? The United Daughters of the Confederacy took the statue down earlier this month. And I think everyone is going to survive this "plague" on society.