I think Cardano is supported by Ledger via the Yoroi wallet extension... it isn't native, but the private keys aren't exposed as you are only signing transactions.
I love the slow and steady approach of the Cardano team... making sure that things work on the testnet before migrating to the mainnet... it does mean that their mainnet isn't quite as feature rich as other cryptos, but it does what it is supposed to be doing!