Answer:
Semicolons are among the punctuations that are misused and misunderstood most than any other punctuation marks. This is because they have been dropped dramatically in the modern literature. Normally semi colons were used in every ten words but today is not the case, because you will come across a semi colon after about ten pages.
Therefore in the given excert, semicolons are used to indicate a long and complicated list that contain individual points that are beneficial and in a continuous form.