But even if you do it through that, SSH is a much nicer protocol than typing on a remote console. You get file transfer, X, agent and port forwarding, terminal window scaling and much lower bandwidth.
Not sure, I haven't used AWS much. Most of the web consoles I have used are like VNC. So no, not really possible to run anything like Zmodem over.
Not that I'd want to either, of course. Bringing an 1988 solution back to fix a conceptual 2022 problem does not sound like a great fix :)
I understand that in some workload types you want to have full autodeployment on servers, using ansible, kerberos, whatever. In that case interactive login is never needed.
But this is a very specific subset of 'servers' in my opinion. A lot of HN contributors work in this so this approach may work for them but it won't everywhere.
There's no need to open port 22 if tools like AWS Session Manager (and GCP's equivalent) are available to you.