With the right tools you can duplicate that grimy sound enough to fool people into thinking it's a sample. Also, playing many instruments isn't actually that hard once you've learned one well, especially stringed. You just have to pick them up and put in a little effort. The hardest part in my opinion is what you mentioned, fingering. I can't think of many instruments I haven't/can't play but I'm strongest at keys and guitar (rhythm and bass). I don't really like playing wind and horns so if I want that I almost always bring someone in who does and is better anyway.
I like sampling when it's done to get sounds, but not actual musical parts. Some of the hardest beats I've heard are sample based but completely 100% original composition.