Coincidentally, I have a friend who got covered by an avalanche last weekend in Breckenridge's backcountry. Fortunately, his skier buddies rescued him. They said he would not have survived without his buddies.

That's generally the way it works. Statistics vary slightly depending on whose data you use and how you massage the data. See for example Comparison of avalanche survival patterns in Canada and Switzerland. But in general all the data shows that a significant percentage of people are killed outright by trauma. Of those completely buried, but not killed by trauma, there is a reasonable chance of survival if rescued within less than 15 minutes. Your odds of survival drop off very precipitously after that. After a couple of hours, you need a miracle.

If your buddy is buried, you are the rescue party. Going for help almost always means going for help to recover the body. That is the cold hard truth about avalanches.

Edit: I'm very glad your friend was OK!

And that is why avalanche beacons are such wonderful things...