I see many DEX (Decentralized Exchanges) like Airswap, 1inch.exchange exchanging altcoins, but not offering BTC. Instead you should exchange first to WrappedBTC or any kind of BTC token.
Why isn't possible to exchange directly to BTC or are they any DEX supporting swap to BTC directly?
Stakenet will add USDT to their Lightning Network based DEX, once USDT is implementing it on their chain, probably sooner actually.
Stakenets DEX is by far the most innovative, fastest (instant trading) DEX you can find, and with their DEX Aggregator, combining multiple DEX order books together, liquidity will be plenty.