Make-versus-buy decisions abound in product development. If you aren't a full stack electronics and firmware designer, then you have to manage the design project with its uncertainties, including schedule. A buy-in gets you moving right away, to address other project issues that require a prototype. You can always design it out later.
Dealing with complex chips often involves discovering bugs in the docs, and a second board spin to fix them. Then you'd better have a good scope and some real knowledge.
Despite its hobby orientation, the RPi is legit.