Queues help decouple pipeline stages, but they do not fix a saturated stage. If
adding queues changes measured FPS, use GStreamer tracing and vvas_xinfer
profiling to identify which stage is applying backpressure.
Sinks can also affect measurements. Display sinks, overlays, encoders, and
filesink can reduce end-to-end throughput. Use fakesink only when you
want to isolate upstream performance, and use the final application sink when
measuring the deployed pipeline.