The current QPACK implementation only uses the minimal feature set of QPACK (i.e. Huffman-encoding and static table). This guarantees interoperability with other QPACK implementations. However, it's not very efficient, since we'll never be able to compress headers that are sent repeatedly. This is where using the dynamic table would lead to significant savings.

See quic-go/quic-go#2424 for the quic-go tracking issue.