We have a similar product at Splitgraph, where we do use FDWs in the routing layer (along with some PgBouncer magic). We recently blogged about adding aggregation pushdown to our Snowflake FDW. [0]
Just a suggestion, your home page's one liner is super vague and confusing. I had to scroll down to really figure out what is it that Splitgraph does...
"Splitgraph connects numerous, unrelated data sources into a single, unified SQL interface on the Postgres wire protocol."
Nice 2 cents! We just launched this LP recently so we're still testing it – we've also got a lot of pages to add this month that will hopefully clarify things.
The basic pitch is for a "Unified Data Stack – an integrated and modern solution for working with data without worrying about its infrastructure." Connecting unrelated data sources is one part of the product, but it also includes a data catalog, modeling, integration, warehousing...
By integrating the discovery, access and (optionally) storage layers, we reduce the friction for a lot of common workflows, kind of like GitLab does by bundling CI pipelines and version control. Even if each layer has some tradeoffs, the benefit of integrating them has a multiplicative effect on the platform itself. And if you need a more specialized provider for one layer, that's fine too – the "data middleware" model makes Splitgraph incrementally adoptable.
But yeah... marketing is hard, especially in the "bag of tools" stage of product/market fit when the optimal messaging can differ so much by use case. Thanks for your suggestion!
[0] https://www.splitgraph.com/blog/postgresql-fdw-aggregation-p...