To your point on if you drop your ledger in water or if usb's are not available in 10 years, as long as you have your seed you can recover your coins.
You can enter your seed into a Bip39 Mnemonic Code Converter which will generate all private and public keys along with addresses where you can then check for the balance of your coins. And then import the private keys into any wallet of your choosing.
RE: VLOG 196: HARDWARE WALLETS ARE SCAMS