Every other class in Dark Souls has benefits, spells or weapons etc. They also have specific stats that help them with those benefits. Deprived has none of those advantages, they have evenly balanced stats, and no starting armor or perks. Is there any advantage to playing as Deprived?
The Deprived class's sole "advantage", if you can call it that, is that they have all-around stats at the beginning. While you certainly aren't given the equipment, you have the stat capabilities to play with any other class's strength once you get your hands on the items without having to invest souls in stats. You have enough Attunement for 2 spell slots and enough Intelligence and Faith to mess with basic Sorceries and Miracles.
However, all the classes' initial starting levels are based on their stats. You'll notice as a Deprived that your soul level is higher than the others. This is because all your stats start at 11. This means that the Deprived's on-the-face advantage of well-roundedness is actually a lie. Any other class at the same soul level could possibly have your stats (with a few adjustments given that many classes have a stat at 12 or more).
In the end, the only reason you'd choose to start as a Deprived class is if you want a sort of challenge run. The initial game may be a bit more difficult than if you started as a specialized class but eventually everything will level out.