Hacker News Reader

And it's horribly buggy, slow, and terrible all-around.

Indeed. When I'm on desktop I try to avoid opening links to images and videos hosted by Reddit.

Is there a greasemonkey or stylish script to hide all submissions from v.reddit.com?

You can block the v.reddit.com domain using RES. https://redditenhancementsuite.com/

You could say that about every new reddit feature since they started the redesign.