This was always one of the most frustrating things for me when I was running forums. I would decide to hire people or bring people on as staff, they would be active for a little while, and then they'd just...
disappear, or do very little for the site other than the occasional post here and there but never really helped with anything staff related. It was incredibly frustrating being the only person who was willing to really do anything on the site to a point where I ultimately felt the need to step back because the passion was no longer there, and I was simply burnt out. The hardest part was always letting go because of how much time, effort, and work was put into it.
I used to try and nudge people in my last round of running a site because I think I was just entirely too forgiving, but eventually, I just kinda accepted fate and started demoting people if they were no longer active, especially after repeated promises of returning to activity. I am very much in the boat of "real life takes precedence over online communities," but at some point, it's important to recognize that you may not have time to accept a staff position in your life at that time, and that's okay! Or simply being staff on a community simply isn't for that person, and that's okay too!
It always makes me wonder why people apply for jobs if they won't show up.
I've heard this happening in real life too.
My favorite is when they show up and just don't do the work or complain about the work load. Usually in online communities, at least the ones I've been a part of, people are eager to start doing staff activities once they're promoted and never really complain. But man, in real life, it's the complete opposite, and people just complain about the work load or just don't do certain parts of the job. It's just wild to me.