Most network protocols, including TCP and UDP, are big endian, so little endian really isn't that ubiquitous. And I imagine a big use case for the binary coder will be for networking.
Most application protocols I've worked with are LE; serialisations like Avro, BSON, capnproto, protobufs, etc. come to mind, as well as numerous other proprietary ones. ASN.1 is a notable exception, but it's also much older.