Where is the rest of the question ?
Answer: 1.5 billion people speak English.
Explanation:
First of all iambic pentameter is lyrical in nature and flows very easily making it easy to remember also its was a convention at the time within poetry (see Shakespear's sonnets) as well as plays. it is also less awkward then basis prose and sounds better this why many rap artist use this system today, remembering that Shakespeare in his day was not particularly highbrow it makes sense why he chose to use iambic pentameter.
The answer is “Topical.” I have to make this 20 characters long, but the answer is topical.