2. The author isn't arguing anything opposed to what you're saying; yes, it can speed up front-end requests by deferring work, but if you build an image uploading system that can't handle 10,000 image post-processing tasks per minute, then deferring image post-processing into a queue won't solve your bottleneck.
The author isn't talking about individual components of a system, he's talking about the entire system as a whole. Even when you're using it to speed up your front-end, you still need the capacity to do the post-processing on the backend.
2. The author isn't arguing anything opposed to what you're saying; yes, it can speed up front-end requests by deferring work, but if you build an image uploading system that can't handle 10,000 image post-processing tasks per minute, then deferring image post-processing into a queue won't solve your bottleneck.
The author isn't talking about individual components of a system, he's talking about the entire system as a whole. Even when you're using it to speed up your front-end, you still need the capacity to do the post-processing on the backend.