If these art pieces are in a private collection that can't be enjoyed by everyone already: Was anything of value to culture really lost? đ€
Would the very fact that destroying them would be meaningful, as well as publicly documented, be more artisticly valuable than keeping the artwork locked up in a vault?
A lot of the art that is currently in museums was once donated by a private collector. Many private collectors will also lend their art to museums for special exhibitions.
Some art in private collections stays private but once it's been destroyed there's no chance it will ever get to the public.