As you might have noticed already, (residential) internet speed does not grow. It is forever fixated at some arbitrary value like 5mbps or 20mbps depending on how benevolent your provider is (*cough* Comcast *cough*). 

This presents a special problem where as the block size grows, nodes running from home starve out and everybody starts moving to cloud servers for hosting nodes. We've probably already optimized the peer discovery so much that it's easy to find multiple nodes to continue downloading blocks from, and I don't think further speed up of the initial sync is possible, especially on artificially crippled residential lines, even if the current ZMQ message channels (at least for block and tx messages) give your Bittorrent magnet links instead.

Some people would like to run Core but they have a crappy 500kbps D-Link instead of a proper router, so there should be some kind of "lite" sync where each of these nodes verifies only a fraction of those blocks (we're talking around 1% here) and they somehow signal the integrity of all the other blocks. Millions of these "lite" nodes each verifying different blocks should provide the same security strength while being fast to sync.