Earlier quoted context omitted.
I worked as a sysadm at at "large" (local scale) UNIX SysV installation back in the early 90s. Everything there connected via serial ports, remote offices got multiplexed over a 9600 baud connection. Back then we had local echo for the sometimes slow link, i.e. printing a spreadsheet converted to 3Mb PostScript, and still only 9600 baud in total. So i know what local echo is. It has nothing to do with prediction :) I…
For me, the advantage of mosh is that it handles network changes seamlessly.
As well as that and protecting unencrypted traffic on public WiFi, I get my ad blocker & other protection and credit card payments are smoother as the payment processors think I am at home not coming from some random address so doesn't ask for extra security details as often as they otherwise would.