There's a noticeable latency in the headphones as it decodes the SBP-encoded audio, and in good headphones there'll be buffering too. There's no back-channel: no way for the player end to work out what the headphone latency is. A2DP is never going to work for video except with players which can deliberately advance the audio track by an adjustable amount, and even then it probably won't stay synchronised as the headphone DAC clock can drift relative to the player.

When listening to music, you don't really care about latency -- or, at least, you care a lot less; you probably wouldn't even notice 0.5s audio-only latency, but that's plenty enough to destroy video.

HFP for phone hands-free kits is deliberately a lower-latency protocol, but at the cost of much lower streaming audio quality.

Peter