Yeah the benefits are mainly when you have many different consumers all of whom want to look at the data in different ways, or when you have many different data

Yeah the benefits are mainly when you have many different consumers all of whom want to look at the data in different ways, or when you have many different data sources in your architecture and want to aggregate them on the fly based on the exact incoming query. If you're writing rest endpoints for an SPA and you have one backing store, then the benefits are not really there, it's just another layer. There are some nice things in relay like intelligent caching portions of the data and only refetching the parts needed, but it is very likely not worth it if you can just handcraft your endpoints and make your consumer change in sync.