The issue is considerably less noticeable when using 2x and 4x Multi-Sampling, and pretty much gone at 8x Multi-Sampling (this can be set in under Quality in the project settings). What almost completely eliminated the problem for me was turning on Anti-Aliasing in the project settings and the camera component. I got these black lines, mostly vertically every time when my camera movement was smoothing/damping out (using CineMachine). MipMaps are enabled because I have dynamic zooming and whatnot, filter mode is biliniar because I need them to have a smoother look than with point filtering when zoomed out etc. I'm using somewhat high-res Tiles, not pixel art, that are packed in a SpriteAtlas. I say it's surprising because it's partly kind of the opposite of what is suggested in this thread. After fighting with this issue for way too long, I just found a surprising solution that, as far as I can tell so far, completely eliminated the problem.