Having an offline local network with no Internet access can be useful for a number of reasons. A few that come to mind are home lab networks, non-cloud IoT device networks, and “closed circuit” IP security camera network. For my network, I set up a separate offline IP security camera network that I am using as a baby monitor system (the quality is so much better and it is more secure than traditional baby monitors because I can lock down access from outside users).
A VPN server can provide an encrypted connection to your home network. It is a great way to remotely access your network since it provides a high level of security. Once you are connected to the VPN server, you essentially become a part of the network in which you are connected. This is different than using an SSH server because you are not directly connecting to a single machine on your network.
There are two common ways of accessing your home network remotely and securely: a SSH server or VPN server. Both options have various pros and cons as is usually the case when comparing two different things. These technologies provide an encrypted connection which is important for security of your network when you want to have remote access to your network. Encryption alone is not enough to guarantee security. You can easily be communicating with a malicious hacker via an encrypted connection.
Historically, DNS is a service that was designed to be unencrypted. Whenever a device from your network is trying to go to a web address, it needs to determine the IP address of the website in order to access it. With the increasing levels of tracking and data sharing/selling, a growing awareness that having DNS traffic unencrypted is not a good idea from a privacy and security standpoint. ISPs and other entities are able to know which sites you visit even if all of your web traffic is encrypted.
When I upgraded to Nextcloud 17 from Nextcloud 16, I noticed that they transitioned to a fancier, rich text editor in place of the plain text editor. The editor seems to understand markdown, which is good because I have been using the markdown plugin to see a basic preview of the text formatting. I use the text editor when I want to edit some of the content on this site when I am away from home so the text editor is a useful feature I use in Nextcloud.