It evolves. Laws, rules, regulations accrue but are very rarely re-evaluated to see if they serve their original purpose. It's easier for most lawmakers to leave things alone. Eventually, the state declines or fails under the weight of a century of well-intentioned (maybe) laws that have outlived their usefullness.
Knowing human nature, the best plan for a state that wants to survive is to set a 20 year expiration on laws. Broadly accepted laws would easily be renewed, but obsolete ones would be allowed to die.
Not a new idea but its a good one. Its basically garbage collection but for laws. Another term for it is "sunset clauses" where a law must have reasonable conditions for expiring instead of being on the books for the rest of time.
That would be chaos. Imagine needing to sign a 10, 20 or 30 year agreement 6 months before a law expires.
> to set a 20 year expiration on laws
Wait, do we need to pass a law for this?
This is like cryptocurrencies.
Every new generation is convinced that all the cruft of the existing system is useless or obsolete so they create a new system without the cruft based on "first principles" or somesuch bullshit. And then through pain and loss they rediscover why all that cruft was there in the original system in the first place. What seems "obsolete" is many times a bedrock principle of the old system that only seems obsolete now because it is/was so effective that the problem it is intended to address/prevent no longer occurs.
Also, legislators review the existing laws all the time. Most "new" laws are just amendments to existing laws.
That's a matter of political culture and state institutions. Finland is largely governed by rewriting laws. Each government coalition has a few focus areas, where they try to do a major rewrite of all relevant laws and regulations. And then there smaller changes to many other laws. The initial drafts almost always come from career civil servants, and there are processes that try to ensure that all relevant viewpoints have been heard before the proposed changes go to the parliament.