No, it's not! Fast charge only exists in the charging head, the data line does not fast charge this statement. The third generation of Apple headphones is accompanied by an ordinary Lightning interface data cable, if you match more than 20W charging head, then charging can achieve the effect of fast charging. If you match the 5V2A charging head, then you can achieve the effect of slow charging. For reference only
Yes, the data cable of the third generation of Apple headphones is a fast charge cable
Airpods3 supports fast charging and wireless charging. The fast charging function can quickly charge both the box and the headset at the same time, and it can charge the headset from 0% to 100% in just 15 minutes.
There is no such thing as fast charging for Apple products