HTTP/2 performs worse than HTTP/1.1 if there's high package loss
The problem with HTTP/2 is TCP head of line blocking. If an IP packet is lost it must be re-transmitted. This means that all the HTTP/2 frames/requests that are queued up through the TCP connection must wait. So HTTP/2 performs much poorer than HTTP/1.1 if there's a lot of package loss. This is because HTTP/1.1 will typically keep 5 TCP connection opens to each domain and loosing & re-transmitting packets in one connection doesn't impede the others
QUIC
QUIC remedies this by using UDP
QUIC provides end to end crypto, paralell streams and no TCP head of line blocking. Google developed QUIC, transport layer and application layer
HTTP/3
IEETF tooks QUIC and create HTTP/3. It uses QUIC as the transport layer.
