I honestly don't think the two are even comparable. Moderating a large subreddit on reddit is infinitely harder and more complex than 4chan. Some of the larger subreddits see more pageviews than the entirety of 4chan.
Moving beyond that, moderators on 4chan are completely anonymous unless they choose to be known. This isn't the case with reddit. Moderators often have to have a long and tenured account history or else they don't really have a shot at being added onto a mod team in the first place. Very few subreddits, and no large ones, will add someone to their team without a history.
This is important because with a history, you open yourself up to attacks. If you do something unpopular, you will get witch-hunted by reddit's masses. I speak from personal experience. People will call your house, your loved ones, send pizzas or worse. You're literally walking on eggshells 24/7, 365 days of the year. And then even if you do everything right, if someone has it out for you, it doesn't matter. They'll still figure out who you are and harass you. It's an added dynamic that just doesn't exist with moderation on 4chan.
Moderating a large subreddit on reddit (a large default, like /r/Pics, /r/Funny, /r/Worldnews, etc) is probably the toughest moderating job on the internet right now. And what makes it tough are the millions upon millions of users.
On 4chan, you're literally a janitor. On reddit, you're a janitor and you're also responsible for community building and everything that comes along with that. It's your community and if you don't build it, nobody will come.