and since my new desktop is linux I've been looking for alternatives. "DarkTable" seems promising but I haven't really got the hand of the UI.
That linked video is by Robert Hutton, he makes really good tutorials for Darktable so that might help you.
Anyway, for non-realistic stuff you can add G'MIC for more filter-options and you are pretty much set for life[1].
[0] https://www.youtube.com/watch?v=zzVXK4eAM5E
[1] http://gmic.eu/
I can't stress enough how good Robert Hutton's tutorial videos are though! They often contain little nuggets of behavior that I missed when first learning a new tool. For example, until I watched his videos I didn't know double-clicking on any curve resets it. Knowing those kind of little things adds up over time.
https://www.youtube.com/playlist?list=PLmvlUro_Up1NBX7VK8UUu...