Don’t forget that Reddit has invested almost nothing into good moderation tools, and most medium to large subreddits use third party tools (that use the API) to moderate.

This means moderating a subreddit will either be extremely difficult (by using the official apps and website), or moderators will literally have to pay reddit to moderate a subreddit. For larger raids or groups of spambots, those costs will quickly add up.

I think things will be very different on reddit after the change, although still not entirely comparable to twitter.