Maybe I'm being pedantic, but laws themselves are objective. At least, they are crafted to be an objective description of what is "right" and "wrong". Said another way, laws exist to objectify the morals of the law's author.
I think what you are trying to say is that laws are not self-justifying. Laws draw an objective view of the world, but we can subjectively agree that we don't like that view and then change it.
This could be an issue of articles: Laws are objective; the law is subjective.
To whit, a Law does not always describing discrete actions and consequences.
To say a Law is Objective is not saying anything, because the Law is necessarily interpreted in any frame of reference. A single Law is necessarily subjective and following this, The Law in aggregate is subjective.
It will never be "fair" because it only very rarely take all of the circumstances into account - as Anatole France put it: "In its majestic equality, the law forbids rich and poor alike to sleep under bridges, beg in the streets and steal loaves of bread."
Neither is it particularly objective - its application, especially in a common-law system, is extremely subjective. (You're bound by whatever the judge in previous cases thought the law was - E.g. in the US "stare decisis" is enshrined pretty much as an immutable rule)
It has never been a framework of "right or wrong", either. It is a framework on how disputes get settled. There is no interest in "right" beyond "the authors of the law at the time thought it was a good idea"
To take a trivial example: Slavery was recognized as morally wrong long before the law actually made it something that was not allowed. The law still allows carceral slavery, even though there is growing consensus that that's morally wrong.
As for "better" systems - there's certainly a large faction of countries making the case a civil law system is better than a common law system. But you don't need a "better system" - the law can only be meaningful if we accept that at all times, it will be flawed, it is not "fair and objective", it needs to be tempered with compassion, and it is our job to improve upon what we have.
At least talk about why you think deontology is better than other forms of norm setting, why the law must be right even though there are many different and contradictory laws in different places, and how you propose to make new rules if not based on a concept of "right" that is independent from the existing rules.
Laws are constantly changing for a reason, "fairness" isn't set in stone nor objective.
Are you American by any chance ? I've seen a lot of American talking like that about "law" as if they were god given, immutable, objective and fair.