It raises the costs of paternity testing. Instead of privately, cheaply performing a test, you have to do it publicly and expensively. This de facto stops many men from performing tests, which is significant and not something you can just dismiss. Legal restrictions on consensual activity is not normal and needs a good justification for it. It's the norm to be free to do as you please as long as all parties involved consent.

Maybe you want to figure out if the child is genetically yours before you initiate divorce.

The legal costs of a divorce are not very high in France (I should know) justice is quite different from the US. And a legal paternity test is 150€, which is cheaper than what most private labs offer.

> consensual activity

> all parties involved consent

Well that's the crux of it, indeed. Most private testing is not done in a consensual way because that would require the assent of the child, which is likely minor, meaning it requires the assent of both its legal parents. If you have the assent of both the father and mother, it's easy (and free) to ask a court to allow the testing.

I'm not sure if you need the consent of both guardians normally.

It is required, but the consent of the other parent is assumed in normal circumstances. In a lack of trust situation like this one, the consent of the other parent cannot be assumed.

It's also a chicken egg problem though. Like maybe if you are suspicious and do the DNA test to find out that the kid is in fact yours, maybe you won't get divorced. I just think that the government should get out of people's private married lives.

I think it's a less obvious test when it's through the mail, as opposed to through a court, which could prevent a lot of undue stress on a child who isn't to blame for their parent's divorce.