I use both and I wonder how exactly I'm supposed to find this liquidity thing on Waves
I don't see any big problems with Waves interface. It just lacks features as a DEX. But it's technologically better than ETH IMHO. Waves and BTS are not really competitors.
Edit: The real competitor for Waves is Komodo which has got Decentralized ICOs, atomic swaps before anyone else, zk-SARKs........And it's always absolutely more secure than Bitcoin. https://steemit.com/cryptocurrency/@vimukthi/the-case-for-pow-as-a-service-komodo-dash-and-mining-algorithms-discussion