base-drafts | Internet-Drafts that make up the base QUIC specification | Networking library

The HTTP/3 spec states that

because the parallel nature of HTTP/2's multiplexing is not visible to TCP's loss recovery mechanisms, a lost or reordered packet causes all active transactions to experience a stall regardless of whether that transaction was directly impacted by the lost packet

While I understand this in the context of cumulative ACKs, I had assumed that selective ACKs would prevent a stall as they allow

the receiver to acknowledge discontinuous blocks of packets which were received correctly

But clearly this isn't the case as per the quote from the HTTP/3 spec above. So, my question then is why does head-of-line blocking persist even with discontinuous acknowledgements?