This is because "fancy, high definition, multi-channel audio" has >40ms latency, so you cannot compare it with Web Audio, which is meant to be real time like in digital music settings, where often <8ms is required. You clearly do not understand the problem you are claiming to be simple.
How can web audio be realtime when it doesn't have a realtime scheduler? That may be driving this problem: the browser's javascript engine not being scheduled in time by the underlying operating system.
