The problem with synchronous generation
If the entire workflow is tied to a single front-end request, any slowdown or failure in one step degrades the whole user experience.
For tasks like detail pages, 4K upscale, and model imagery, a viable production approach requires a real job state machine with submission, polling, retries, and packaging.
Why it matters beyond engineering
Asynchronous execution also determines whether credit settlement, rollback behavior, queue visibility, and multi-user concurrency can remain consistent once the product is live.