It's more nuanced than you are presenting here. The obvious middle ground is the use of "Poison Cabinets" where certain works are deliberately and explicitly separated from their contemporaries with obvious labels explaining that they express ideas or opinions known now to be harmful. This way they are not lost or erased but also not treated as if they are perfectly normal and acceptable.

For another thing, there is also at least some element here of the right to be forgotten. It's obviously different for groups vs individuals but our systems should allow some amount of agency to people who regret things they have produced in the past and wish for them to be forgotten.