I was a contributor to a sub with a specific interest group (think something like your favorite programming framework). I got some value out of the community and so when someone suggested 'it would be really nice if a sub existed for xyz' I just went ahead and made the subreddit and was like, well here you go. By default, when you make a subreddit you're the moderator.
Then once that subreddit grew a little bit two things happened: first moderators of similar subreddits asked if I would be willing to help them out on their subs. The second was that moderators from other subreddits who enjoyed the community would reach out and ask if I needed any help moderating the sub. I both cases I said sure and eventually I ended up just being added to a bunch of subreddits as a moderator.
I would spend about an hour a day doing it and I think I kept it up as long as I did for the social aspect of it - I didn't want to burden the other moderators by leaving.
Then there was a highly politically charged let's say discussion that cropped up on the subreddit around some specific language (think similar to the default git branch being called "master"). It was exhausting to moderate, and it all suddenly felt like it wasn't worth it.
I also said to myself, hey I've got a lot to lose here, I've got a high paying job at a top company, and what happens it someone upset about this issue decides to email my employer and cause trouble? That could have real consequences for me. I'm taking a risk here and it's no longer worth it.
So yeah, I deleted the account and just walked away.