Very short answer, which is also a question: What makes you think those things aren't done? Short answer to all your questions: it is a much a people business

Very short answer, which is also a question: What makes you think those things aren't done? Short answer to all your questions: it is a much a people business as it is process, tools and physical goods business. Legacy systems. Global customs. Auditability. Existing operations. Global compatibility of documents. Long answer: Your local university library probably has some shelves of books on the topic.