If it's an open source/community thing then hopefully there would be some sort of consensus on which exchange is the best for each area. If it is private then the company could verify the trustworthiness of the exchange.
Possibly this could eventually be used to bootstrap a some implementation for an ID blockchain (or sidechain?). Because..... it would be nice to make the choices and the process of choosing the exchanges that the community determines to be as clearly shown to the user as can be.
The "software power" is the time we all take to track everything down. The searches and forum verifications. You would still need the identity/residence stuff but if the app handles it via APIs then it is possible that some double steps could be avoided (sending a scanned ID to each exchange, etc.).
Sounds like alot of grey matter and mouse clicking might go into that also, but having an API for account validation sounds like a smart move for sure. Maybe some kind of web-based store for documents could be used to discourage the innately higher security risk of keeping multiple copies of user data at multiple exchanges.
Also, if Zero Knowledge Proofs became a thing any time soon, an ID chain and the verification API could be made to use them to allow the users to use willing exchanges to do so with even more privacy. The exchanges need not know all the users details, only that valid details were submitted to those who actually require access to them.