The point is that the interface to Bloop (or whatever 3rd party SaaS product) is just plain text. In programming parlance I would call this a facade [1] on top of GPT-4. The benefit is that you, the end user, can just continue typing things like "Where do we create our database pool?" in a search box, but under the covers Bloop can use GPT-4, but then eventually upgrade to GPT-5, GPT-6, or some other much better currently-super secret competitor version.