I very much agree with everything you said. My biggest complaint with dex's or even just "non-custodial exchanges" (Binance dex) is the lack of trading pairs. I use ddex or poloniex dex when I can, but the exchanges are more often then not, not cross-blockchain compatible. Really hoping this changes in the future.. But I fear there will have to be a lot more pain for users (loss of funds using cex) before the large majority of people see the real value in decentralized exchanges.