> It still seems to me designing applications or web services is so hard that it's just easier to hire thousands of people to do customer service and having people to come physically to do things.

I'd love for this to be true, but every business nowadays sees employees (except maybe whatever group is core to their business) as a giant cost centre. Every employee cut is money saved. Hence customer service consistently being shit, since it's an easy place to skimp on. Now, the doorman's fallacy could be applicable here; good customer service will create repeat buyers and good word of mouth, but I doubt you need to put that many people into it to make it good. Thousands has to be well past diminishing returns. Even if only 20% of people find the happy path in some stupid web app, that's potentially thousands of man-hours that customer service didn't have to provide, and thus a lot less employees you don't really need.