Consumer protection laws that forced companies to simplify agreements were a response to the massive increase in complexity without such laws being on the books.
But there’s an even easier, non historical, way to see how “competition” does nothing to solve the problem of complexity in agreements.
The agreements to rent an apartment, or to buy a house, both of which are among the most complicated agreements the majority of people will sign, are far more straightforward in most states than buying a $2 song off iTunes or signing up for a 1 month membership off Spotify.
There is a lot of evidence that consumer protection laws have had massive effects in making the agreements more standardized and transparent and reducing shady and fraudulent behavior.