Speaking as a non-lawyer who works in the legal industry, I question the idea that legalese is generally more precise and unambiguous. From what I've seen the purpose of a lot of these legal incantations is actually to be more vague.

This isn't necessarily a bad thing. A more precisely worded contract, for example, is arguably more likely to have unambiguous loopholes that people can abuse without you being able to easily fight back. The well-known reductio ad absurdum of this phenomenon is Etherium smart contracts.

You see this in laws, too. The US's Federal Rules of Civil Procedure and associated case law, for example, contain all sorts of explicit refusals to say things more precisely. The stated rationale, here, is that it's impossible for the people drafting these rules to anticipate every possible situation and contingency, and instead they must trust that reasonable attorneys and judges are able sort things out in the course of litigation.