Are you using assisted culling in Lightroom for culling? As yeah, thats just missing from Darktable and you would have to use another (opensource) tool to do that.
However if you are still manual, I dont agree once you have learned the keyboard shortcuts, that’s as fast for me in both, or in my current tool of choice, photolab. Even just using 1 to 5 to do basic culling with auto advance is a game changer for manual review.
Editing really depends on your workflow, if you have a lot of similar shots you can just copy and paste a working set across everything thats similar and then manually tweak. Even if the shots aren’t the same just applying the usual set of modules with some sensible defaults across photos is very helpful. I used to keep one back from my last set as a template.
Only thing I don’t like with Photolab is that there is no Linux client. I ended up getting a Mac because I liked the latest version of Photolab so much for my workflow. Deepprime xd3 is just ridiculous at cleaning up my high ISO photos.