If removing statues of racist people does not harm/ have a negative impact on anyone, why do we need to be so attached to tradition and history, given the positive impact that removing statues will have on people affected by systemic racism? We often update our views and let go of tradition.
Other countries (including African countries where slavery was normal) might not remove their statues as they have decided as a society that they can live with the harm those people carried out in those societies. It's up to British society to decide on the statement they want to make.
It appears that those who want to remove statues want to make a statement about the effects of historical slavery on today's society. It has a symbolic effect of focusing the issues on the inequalities. If race is just a cultural creation and people were discriminated against for centuries in terms of housing, education, jobs, ability to create and accumulate wealth based on their race, which has created the inequalities we see today, why not draw attention to a historic wrong by removing statues to acknowledge the reasons for today's inequalities? Especially if the statues represent wealth created for white Britain at the expense of slaves, who had few if any human rights as they were considered property and not people. Maybe it depends on whether people think the achievements of slave owners can blot out the historical wrong of slavery. Because I think that is the impression created if the statues remain in place rather than being moved to a museum. I personally am not affected by the statues as I have a comfortable middle-class life, but I can understand why they would be problematic for many black people facing systemic racism.