SOAP/XML, WSDL, and related tooling are not always a walk in the park, but they certainly haven't faded into history. Indeed there are plenty of pathological cases, and overblown, tool-bound APIs designed by architecture astronauts, but it is also possible to publish and consume them in a manner just as simple and straightforward as the examples suggest. Taking just one example from my own experience, Salesforce's SOAP/XML services have proven easy to use, sensibly managed and versioned, and far quicker than hand-building structures to manage "simpler" REST.