Why is dex fee so high

I tried Uniswap recently. Aside from the clunky UI on both the website and android app (I don't have iOS device), the 0.25% trading fee is just too high to compete with centralized exchanges.

I get it, LP need to be paid. But isn't lower fees for higher volume a much better strategy? At current fees, nobody should use it unless they are religiously believing in DEX. How is a theoretical zero volume going to pay LP better than at least some volume with a fee better than Binance (0.1%)?

I think there should be a fee market where LP specify how much fee they want to take. If they set it too high, their liquidity will never be used, so they never get paid. The free market will keep it at a reasonable value. I believe that value will be much lower than 0.25%.