I think it depends on the specific terms of the prenup. I mean, some are fair and take into consideration the opportunity cost of certaine roles. Others are skewed to one side and are not fair.

The problem with prenups is that many times are only considered with a short term view. They don't take into consideration how things change through the years. Or that if conditions change over time, maybe what was fair then, wasn't latter.

For example: a complete finance separation is fair if both partners are allowed to have careers with the same opportunities. The second one of them has to make concesions in their career for the other, the part who makes concesions should have some kind of compensation for the opportunity cost. Compensation might take the form of the other part making a concesion too. But if it is always the same part who is making concesions, then the pre-nup should have clauses or modifications to reflect that.

Negotiation something for the next 30-40 years, might be very difficult (you lack information), so probably pre-nups would need to be revisited at least every 5 years to review this kind of thing. And limits to them should be applied to keep it relevant. But that is just my oppinion about contracts.

If prenups are "insurance" in case of break up, insurances in case of "hiden cost" within marriage should also be there.