there are types of interactions (e.g. medical treatment, certain business relationships, and sex) that are societally considered not appropriate to have with a family member

reason often given is because the power dynamic is unavoidably influenced by a family member’s sense of obligation to do things for family that they wouldn’t consent to do otherwise

which I believe is quite a valid concern

but then there’s also like. literally everything that society DOES expect you to do with family

all of which is influenced by the same damn problem

often 100x worse