I asked my self the same question, scanned the linked article and did not find any matches for "screen". So please, could you tell me in short, what the benefit is?

They are a bit orthogonal. When you have a flaky connection, screen will help keeping your stuff alive on the remote host but you still need to reconnect all the time the connection drops. ET and mosh will make it look like your connection never dropped.

Just my guess, but it could be that screen is older and perhaps less used (or at least written about) than tmux.

Thanks! I was wondering the same thing, and this helped.