I think the lack of acceptance to lightning by crypto in general is the problem. “Privacy coin” communities like to say Bitcoin is too easily traced and expensive to use. Some might agree, while others say that doing this is the true cost of bitcoin.

Generally, onchain TX for darknet markets requires no-KYC BTC and coinjoins which will cost more and require users to know how to control each UTXO.

Unannounced LN channels are ideal, but don’t seem to have been given a fair go so far.