All sitcoms use a laugh track of some sort.
Arrested Development, Sunny in Philly, and Curb Your Enthusiasm don't and those are some of the funniest shows around.
Those aren't what I'd call traditional sitcoms either. They may be funny to you, but to middle America, they're not. Arrested Development couldn't even make it on a major network and is now relegated to Netflix.
Conduit content providers like Netflix may put a couple of the "major networks" out of business in the next ten years if they don't start doing better.