From my experience it's extremely rare even for large companies to directly deal with ODFIs.
Typically there's AT LEAST one intermediary payment processor (like Chase Paymentech) involved in the TX.
The downside to this is merchant has to register with multiple processing entities but things like "send and forget" APIs (so no need to batch things manually) - which makes it easy to combine ACH and CC payment acceptance in the same system, reporting/reconciliation, out of the box UI merchant can use to look up transactions etc etc outweigh that inconvenience.
Typically there's AT LEAST one intermediary payment processor (like Chase Paymentech) involved in the TX.
The downside to this is merchant has to register with multiple processing entities but things like "send and forget" APIs (so no need to batch things manually) - which makes it easy to combine ACH and CC payment acceptance in the same system, reporting/reconciliation, out of the box UI merchant can use to look up transactions etc etc outweigh that inconvenience.