I think we're rapidly moving toward user self-service. Once upon a time secretaries took shorthand and managed all the correspondence. Today, secretaries are a thing of the past, giving way to executive assistant, or, in most companies, the role is delegated to everyone. Executives, even, manage their own calendars and emails. Excel was purview of the technically savvy. Today, everyone knows how to create and use a spreadsheet. Data and BI are no different. I work in IT and, officially, my title is Senior Software Developer. But, I consider myself a Data Engineer (I disagree with the way the title Data Scientist is often used). I get the data out of the operational systems and into an understandable format. I then show the business how to access that data. They can use any tool they want; Excel, Access, Qlik. Unfortunately, most business analysts are not skilled enough to manage a Qlik (or PowerBI) data model. So, I usually need to do that for them too. But, we are really pushing for user self-service.
Whether you build or buy, the key is going to be in data governance.
Another point to consider in the build/buy decision is scaleability. Rarely do the end users know what they want or need until they start playing with the data. If you buy a tool or final solution, how easy is it to change?