I find this utterly bizarre. Once upon a time, if you wanted to left pad a string, you would just do it. A while later, people discovered that you could use a library. (I’m joking a bit here, but libraries are genuinely useful.). With a library, you get to pick from various schemes and schedules for updating the library, but you have a degree of control.
But now apparently you’re supposed to use a web API and depend on an external service. This has all kinds of downsides: it has latency (and potentially tail latency). It has larger security issues. It doesn’t work in many sandboxes. It requires an asynchronous call. Callers have to handle timeouts and retries. (If you left pad a string with a normal library, it either works or it doesn’t. With a web service, it can fail transiently or give wrong answers transiently.). It updates on its own schedule, without notice, and cannot be rolled back. And it can charge an utterly outrageous per-call price, so instead of merely profiling and debugging slowness due to making too many calls, developers also have to worry about inadvertently spending hundreds of thousands of dollars.
Replace “left pad a string” with “generate a PDF” and you get this. Why is this desirable?
I suppose things like this may partially explain the stunning slowness of bank websites.