I non-rarely have links with ~0.1% packet loss. If you get even just that much packet loss, and a long-distance link, you _very_ quickly drop below 10 Mbit/s, i

I non-rarely have links with ~0.1% packet loss. If you get even just that much packet loss, and a long-distance link, you _very_ quickly drop below 10 Mbit/s, if the other side can't do fancy selective ACK and similar additions. While I might be able to do something against this, as long as I control one node on both sides of the lossy channel, I can compensate with a little bit of FEC. I might even be able to operate lossless, using a fountain code to add more parity for each data bundle as long as my recipient node continues asking my sending node to supply more parity. You are right though, for unicast networks there is little use of L3/L4 FEC. Maybe with the age of IPFS and other content-addressed networks we will come back to broadcast-FEC networks, like those used back when for 3GPP multicast services like e.g. TV.