Web Services turned out to be impractical and a non-starter. We added a ton of code for connecting to Salesforce back when Web Services was the way. This did not pan out, in part because they charged you too much for API access, which of course they needed to do because Web Services is so complicated.
Big Business pivoted to using Modern API's that take a modular approach. This provides a fast and practical solution to connecting to anything that supports a modern API. What is a Modern API?
This Solutions explains, some. (7004)
Web Services was a best of breed solution to conecting systems, like Big Business to Salesforce. Unfortunately it was perhaps too detailed, too intricate, too fancy.
Enter the Modern API. We are referring to an ever-changing approach to connecting systems that uses the latest technologies. It continues to support the former latest technologies for a reasonable time. And it is able to change out technologies in modular fashion to continue working. As such, it is a blizzard of acronyms like REST, XML, JSON, HTTPS, SSL, TLS.
Do you care? Big Business does not. Big Business takes a modular approach to using APIs. Where there are often three ways to do a task (old, new, newer), it knows all three. This is because it uses them interchangeably with different connections.
Bottom line, this saves you time and money because whether you are customizing a connection to your favorite new service, or putting in a Upgrade and also hoping it changes out the connection to your favorite old service (often it does), any change is cleaner because of the modular design.
Unfortunately it means Big Business does not support Web Services because it has proved too time consuming and too costly. This means some venerable services are not available. If you were pointed to this Solution, it may be because you were asking about connecting to one of these services. The answer is likely, No Thank You.