What it covers
Enterprise architecture looks at more than how the IT systems interact. It takes in stability, availability, sustainability and agility, and alongside the technical side, the processes that go with them, because an architecture without the workflows around it is just a diagram.
Why the scope grew
IT services increasingly bear directly on a company’s products. A device installed at a customer sends system data back; that gets analysed centrally, and where something looks wrong the maintenance can be planned before anything fails.
Services like that add value to the product and are a competitive advantage. For them to be possible at all, IT has to be involved early in product development, so that the framework exists.
What follows from it
An offering like that needs more than the mechanical or electronic engineering. It needs the IT department, and usually further applications and services. It also forces a decision on whether the collected system data is stored and processed locally or directly in a public cloud.
That decision is not purely technical. It hangs on data protection, on the contracts with end customers, and on who may analyse the data later.