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?
Currently, there are still many DEXs implementing BTC trading pairs with many exchanges. IDEX is one of the earliest and most well known DEXs. In addition, we have Binance DEX but it is quite limited in terms of trading pairs. these will be the DEXs you need or you can trade in CEXs, it's still easier and has a larger volume.