This might go slightly against the spirit of Lemmy, but for subreddits that act like a content feed where losing comments isn't a problem, I've created a reposter bot to mirror subreddits on Lemmy.
It has proven quite popular on !100yearsago@sh.itjust.works . If anyone wants me to mirror a similar sub just drop me a comment
There already seems to be one that has activity: !HistoryPorn@lemmy.world
I guess we could ask them if they'd like my bot to repost stuff from the subreddit there too though
Haha, yes I can try adding them!
There's no easy way to add more because the reposts are just made by a program that I've set to run on my laptop. If you're feeling particularly techy you could try running it too if you like: https://github.com/albert-tomanek/reddit-to-lemmy-reposter