I really don't think Reddit, especially in the time that the Tumblr ban happened, was actually more moderated than Tumblr. Tumblr was just the one that got their moderation found not to be up to Apple's standards first at a time Apple needed to make a statement that they're "not like those other big tech companies". Arguably this was also a warning shot to other social networks like Reddit who did up their moderation afterwards, for both good and bad.