Finger independece is quite important. Fingers are all individually independent, of course, but what if you need to one thing with one finger, and something with the rest, all at the same time?
Here's one of my vids on doing just that. Anchoring the 4th finger on the 4th string, playing a D to match the open 3rd string, also a D note. While 4th finger is anchored, the rest continue playing the tune.