I find it hard to believe that everyone on here really believes that statues and other memorials should never be removed, taken down or changed as our knowledge grows. Perhaps the best known recent example before Colston in the UK was Jimmy Savile. A statue was taken down, as was his headstone and memorial plaques. Streets, a foot path, buildings were all renamed.
As for Colston, the full context is rarely reported. The statue was erected in 1895, 170 years after his death and almost a century after the first legislative attempts to abolish slavery. When his statue went up, slavery was fully illegal and the source of his wealth well known. Concern really grew from the 1990s and there was eventually the possibility of rewording the plaque on the statue. However this did not happen.
If we go outside the UK, I’m sure we all remember the toppling of the statue of Saddam Hussein amidst massive celebrations,
Further back in the 1950s, Destalinisation meant statues and monuments disappeared overnight and place and building names changed
More recently has been the controversy over Franco and the eventual moving of his body from the Valley of the Fallen
Finally, in 2018 I visited the Baltic States that had suffered so cruelly under both Nazi and Soviet occupation until recently. It was common to see statues of. their former oppressors had been moved and lumped together in a field - in one case near the many graves of some of their victims to make a point. Obviously street names, buildings etc had all been renamed.
So I’m just making the point that our past and the people in it are constantly revisited and how we mark them is reevaluated. There really is no absolutist position that says for example all statues ( and other memorials) should go or should stay is there? Like just about everything to do with history, it’s complicated