It is written by the “plain English” method, but is long only because it is a “framework” contract, designed to cover all versions of the services for various situations, to give flexibility as client needs or transactions tend to cross over mixing with other services, and to accommodate repeat business with satisfied clients under the same contract without having to re-sign.
Please keep in mind that the majority of provisions are not “functional” (practical), but rather are required by law to be there only for “compliance” with various banking laws and regulations governing the bank.