It feels like a compelling property here is to have a "single point of continuously increasing quality"—that is, one changing chunk of code that is continuously

It feels like a compelling property here is to have a "single point of continuously increasing quality"—that is, one changing chunk of code that is continuously improved and battle tested as more and more users report issues that require workarounds. (But of course ever-changing externally hosted web services like these have their drawbacks.)