create a Lemmy instance that mirrors reddit, rather than have bots post reddit posts onto main Lemmy instances, create an instance that mirrors specific subreddits on request, including the comments of their posts, and allows Lemmy users to comment and reply back, where those comments are also propagated to reddit so that replies and discussion are mirrored also.

I guess you were not here during the alien.top debacle…

This is exactly what I was doing with Fediverser, and I was really close to implement full two-way bridging, but instead of supporting the effort the great minds of Lemmy decided that the any sort of automated content was spam and unworthy of attention. Instead of looking how the system for onboarding users would make migration 10x simpler, I had to deal with skeptical admins and users who covered their noses at anything or anyone trying to fight Reddit on their grounds.

They appear intent on recreating the problems of reddit here.

The problems regarding Reddit-the-corporation are orthogonal to the problems of Reddit-the-online-space. Which types of problems are you referring to here?