[wting]

> It does, though. Your karma basically determines the visibility of any new post you try to make.

User karma has no impact on the default sort ranking[0]. The source code is available here (as of ~2018): https://github.com/reddit-archive/reddit/blob/master/r2/r2/l...

> And low-karma or new accounts are de facto shadowbanned.

User karma is impacted by mods' use of AutoMod on a per subreddit basis or fraudulent[1] accounts, but otherwise there is no site-wide application of user karma.

Source: I spent some time experimenting and implementing alternative rankings at Reddit.

0: Subreddit hot score, not applicable to logged in users' default feed.

1: Shadow banning (vs direct banning) fraudulent accounts makes it more difficult to reverse engineer signals used to identify malicious accounts.