In 2020, I observed less than any year since 2001... this year, I've had even fewer opportunities for observing. Sky conditions have become worse. In winter, we have fog; in summer (for the past 5 years) we have smoke from wildfires. Right now, conditions here are untenable in the Central Valley of Northern California. My most productive observing seasons are Spring and Fall. So when observing is a no go, I concentrate on other interests.
CN provides a platform for our social network to share information, ideas, and opinions. If you allow, you can spend inordinate amounts of time in this forum, until one day you decide that too much of your time is spent here. This has happened to many members. From 2017 to 2020, there was hardly a day that I did not check in to read new posts about NV. Today, I check the NV forum about every 3-4 days.
A couple of months ago, I emailed Eddgie. He is fine, is still observing with NV, but decided to step back from CN as he was spending far too much time here, answering questions and giving advice. He said that what he enjoyed most about the NV forum was reading observing reports, but that observing reports had become fewer and farther between. Having just scanned the first page of our NV threads, I only saw one that dealt with observing... all of the others are about equipment. Ed did say hello to everyone and if you have a specific question for him, you can PM him.
There is a slow turnover in our forum participation. When I started actively reading NV posts in early 2016, the members who posted regularly were very nearly all different than those who post today. In 2005, when I bought a Collins i3 NVD, there was very little information available that dealt with its application to astronomy and few NV posts actually existed in the Eyepiece Forum or the Observing Forum. Today, almost any question a new user might have can be answered with a search here or with a Google search, which usually leads back to this forum. There is a wealth of information already written about NV, and many of the questions that are asked have been answered many times.
Most NV users are pretty active observers. We use NV to see more and it does present the means by which we achieve that goal. But the total number of NV users has always been small, compared to glass eyepiece observers. This means that when a few NV users take a holiday from posting, it's pretty obvious.
There are two more reasons why posting sometimes falls off. One is when a violation of forum rules occurs and posting privileges are revoked. We never know when this happens because the rules also prevent disclosure. But it happened in 2019 to several EAA and NV users who violated a new image posting rule that was later rescinded. NV posts fell like a rock for about a month. The other reason is when people who post are put down by someone with a different opinion. This happens occasionally, and when it does, it makes people wonder why they should spend their time here. It's OK to post a different opinion, but "attacking" someone's opinion has always been prohibited by the rules for good reason.
Those are my thoughts... but the current low volume of new posts might be due to the smoke from California that currently covers more than half of the US. That would be the simplest answer.