Yeah, but it's a stablecoin pegged to the USD. This allows other projects, like dydx to create derivatives products based on this peg. You have other protocols that use the DAI peg to create stock market derivatives. Today, I can trade ETH for a token pegged to AAPL's stock on the blockchain.
I remember showing a friend this really crappy online video stream in the late 90s, and I think he said something like "How can this ever be useful? I can rent a DVD and watch high quality video without any interruptions." He wasn't wrong.
Yes, but right now it's much more stable to be holding that than one of the pure crypto assets. Anyone can make a stablecoin backed by another country's currency.