My objection to precedent in law making is two-fold:
EG. With regard to land rights, ownership, right to defy, etc. many of the problems we are now experiencing of the land availability, usage, even 'nimybism' etc. has been perpetrated via the use of precedent.
Much of the law that effects land were made originally, as you say, as far back as the 12th century, when Barons etc. either owned (usually by a royal bequest) or for use in perpetuity (handed down etc.). The 'rights' to land given or taken by force have been enshrined in existing law via many twists and turns via this construct of a constitution based on precedent.
I was once a victim of this when I bought a house advertised as Freehold, but then found it was subject to something called 'Chief rent' and was paid annually to the estates of the Earls of Stamford and Warrington, or their heirs. It was a relatively small amount and could only be increased each time the house/land were resold. This is what got me interested in investigating such matters.
Thankfully some years back the government was able to force amendments to such laws that allowed this 'deal' to be de-bunked... this was by allowing a current owner to 'buy out' the chief rent clause, in my case it was some £1,200.00. This could be advantageous to some degree when I came to re-sell ... .. i.e. without 'chief rent applying, but the saving to me would require me otherwise some 70 years to get back what I spent.
Of course Land isn't the only thing affected by laws made or changed because of precedent, and as you say 'learning from what went before' is generally a good thing. However, as we see today with the massive demand for houses at reasonable costs/social housing etc. is growing fast, precedent will have little impact.
My second objection is that if as expected our climate-change scenario closes in increasingly swiftly on the lives of everyone and every thing on this planet, what went before in law making, of every kind, is unlikely to have much relevance. .
Also this current exchange/attempt of understanding I am having with many on the Caf about what constitutes 'good law', is showing how confused and confusing its going to get, when people who are trying to make the law do things it was not intended for, to people who believe they are trying to protect civil liberties and the right to protest.
In my opinion (and it is only a personal opinion) the world is going to hell in a hand cart, unless we get ahead of the curve in many things, but especially in law making. There is more need now, more than ever, to look forward and try to anticipate in terms of the framework of law, at what will work, be fair and enforceable. Very little in our past will prepare us for what is coming.
It seems my opinions are not widely shared, fair enough, but as
@Buster15 has said, I have a right to present my opinions and others a right to disagree. (Politely I hope!)