I think the value here is around starting with a known default. If someone hands you a contract which consists of a known boilerplate plus three changes, then (assuming you're already familiar with the boilerplate) you don't need to carefully read the entire contract word for word, you only need to look at the three changes, plus whatever customizations you'd like to propose. For the vast majority of the terms where neither party feels a need to deviate from the standard, you get two benefits: (1) the drafting party's lawyer won't put in onerous terms just to see whether they can get away with it, and (2) you don't need to read it carefully, because you already know what it says.

(This assumes some mechanism for ensuring that what is claimed to be a copy of the standard boilerplate, is in fact such, and has not been sneakily modified.)