There's a well-established answer to this that I've done for years that satisfies both and it's the BFF pattern. The crux of which is an orchestration tier. A simple pass-through API gateway which can interface with all your thoughtfully-designed, single-purpose APIs, extract and transform one or more payloads and serve up a single payload that maps one-to-one with a frontend. I've deployed this architecture for years on some large-scale sites. It works very nicely. Bonus is that you can manipulate and even swap out entire backend pieces without worrying about your frontend.