Reddit demolished Digg because it offered people fiefs rather than just karma.
Sure, you could comment on Digg, but it was a pain and not good for conversations, and that meant there was less to keep people around when it seemed like the company was started to put their finger on the scales for URL-submissions.
Reddit did not win due to it's features, it won because Digg said it doesn't matter what the users think, we will redesign the site and change how it works regardless of the majority telling us they don't want it.
No it wasn't, because it wasn't threaded. You had to linearly scan all the comments to see if anyone was replying.
Reddit had subreddits long before the migration. Reddit was a not very used site that had all the features.
It was Digg that made the decisions to force people off of it, not anything reddit did outside of having a space available that worked.
This broken record is still going at it, going at it, going at it, ...
And yet, ChatGPT is number one, by a far margin; where's all of this "people could switch in a day if they wanted"?