Isn't that the whole point of AWS and their competitors? The savings of passing the problem off to domain experts to work out all the details often outweighs the benefits of having a solution that is 100% customized for your business.

For many companies (even large companies) it is cheaper and faster to use a service like this than build an in-house solution.

Not to mention that if you want this built for your company you call up the BI provider and tell them to send some consultants over to build it for you. You might train one person or possibly two at the most to be able to make tech calls with the BI provider. Much easier for a company to say "I want a dashboard that reports X, Y, and Z" and then the BI company scurries off, builds it, brings it back to you, and you hand over some cash for their effort.