Frankly these are useless. SSH is secure by default and will never support algorithms that could be possibly broken. Same for TLS 1.3

Docker bypassing ufw is very bad

If you disable password authentication, and use public key authentication, yes.

The reason for downvotes is comparing apple and oranges, and also throwing FTP in the mix!

Let’s consider SFTP and nextcloud. SFTP is a secure respected protocol for file transfer. If you use key authentication and disable the password authentication, it approaches to be bulletproof security wise. SSH has rarely had a vulnerability that would allow attackers in. It’s even have post quantum cryptography. It’s rather easy to set up. But it doesn’t do more than file transfer. It also doesn’t have a lot of GUI apps.

Nextcloud is like Dropbox. You can find A LOT of things in it (though frankly the quality of most of them may be low). File transfer is just one of the things that it does. It uses https, why? Because the web technologies and developers have focused on this versatile protocol in the past decades. You access internet through port 443 not 22!

If I want to backup data or transfer files, I use SFTP. Over the internet, I trust SFTP not nextcloud. For other things, I use other tools such as Synchting, nextcloud etc. Synchting allows syncing over SSH.

Wireguard is what you want!