There are still arguments about whether they are needed or not. Personally, I still use them only because a time or two I had a problem when the services started in the wrong order, AND because I have a task I use to set up the dependencies AND the automatic, so it's a 1-click thing to get it all working right.
However, in theory, and in very common/real practice, simply setting them up to Automatic is/should be enough.
There is one other advantage to dependencies. If you set them up, then when you restart the interface, ALL the services restart as well. That's simply a right-click option saver when you're troubleshooting, so a very small thing, but since that's what I do for a living... I like it.