Parties have archived the data from pushshift, which cover a lot of Reddit history.

kagis

https://academictorrents.com/details/1614740ac8c94505e4ecb9d88be8bed7b6afddd4

Subreddit comments/submissions 2005-06 to 2024-12

This is the top 40,000 subreddits from reddit's history in separate files. You can use your torrent client to only download the subreddit's you're interested in.

I mean, that won't have the past half year or some low-traffic subreddits, but...