You make a good point. The Colosseum as history might be worth preserving, like Auschwitz; but not as an object of pride.
Here in the USA, when schools become mass-murder sites, the tendency has been to replace them https://www.cnn.com/2022/05/31/us/schools-after-mass-shootings-uvalde-texas/index.html .
What Have The Romans Ever Done for Us... - Monty Python’s Life of Brian
https://www.youtube.com/watch?v=Qc7HmhrgTuQ
I’ve been on a guided tour of the colosseum, they talk extensively about it being a place of evil. They also talk about how it was targeted in a least 3 major efforts throughout history to tear it down. It only exists because it was too massive. It sits in its current state because of those efforts. Eventually, it was determined it was worth preserving. And, if your catholic, it’s been exorcised and purged and crosses and other christian symbols have put into the structure all around the structure.
Not even close to similar