Banning books on a country level may be silly but curating what is allowed in a school library is not. Which is exactly why people with an agenda want to conflate these two.
The librarians should curate, not the parents. The parents are welcome to decide for their own children what is permissible and not, but should have no authority to prevent others' children from accessing materials they do not find objectionable.
Why is it about "parental rights" when it comes to anti-vaccination, but authoritarian control mechanisms when it comes to someone else's kid reading a fucking book?
If your goal is what to have parents decide what their kids can read then the only way to do that is to have the shared (e.g. school) library carry the commonly agreed upon subset and individual parents who want their kids to have access to more to provide those more controversial book at home. The only reason to call to have books other parents don't want their kids to be exposed to in the school library is if you want to override their choice and make those books available to kids other than yours as well.