The price is rising because Curve is being used more than ever before. The demand will only increase as institutions and banks get involved in this space and need platforms for stablecoin swaps. Curve is positioned as the market LEADER for stablecoin swaps and that is huge... not to mention they are adding regular pools for all other ERC20 pairs soon + zcash pools on Curve
Yes but there are so many DEX based stablecoins swap projects and you can also do that through Uniswap. Since CRV is open source project, it isn't difficult to fork it and create something similar.
About institutionals and banks, they have no reason to do that via DEXs. IMO, they are using centralized exchanges which have more liquidity and security plus the fact that they can hide their tracks since their trades and deposits are not visible like they are in Ethereum blockchain.