Sends in the clear, no error checking, the nc command is promiscuous while its bound to the port. No crypto or compression to slow you down. Just a raw pipe of bytes
Its a bad idea, part of the forbidden codex known only to old, irreverent graybeards who know better but don’t care anymore. There are better ways that are both more reliable and better practice.
You might want to look into using passwordless SSH keys within your script (see ssh -i) which isn’t the most secure.practice on multiuser systems, but is Okayish in Devops and backups. Add other factors like aggressive allowed hosts settings on the receiver, and rotate the keys regularly.