On the dialog that allows you to set a wallet password, there is a little checkbox that says "Encrypt wallet file":
If you enter a password and the box is NOT ticked... then your wallet file is basically "human readable" plaintext in JSON format, but your seed and/or all private keys are still stored "encrypted" within the wallet file... like this (obviously, I blurred the encrypted seed and xprv... but you can see the xprv starts with a "Q6" instead of "xprv"
):
If you enter a password and the box IS ticket... then your seed and/or all your private keys are encrypted within the wallet file... and then the whole wallet file itself is also encrypted, so you can't read any of it... (NOTE: same wallet file as above pic but with encrypt wallet file ticked):