In addition to “encryption at rest”, also consider that your devices might be exploited over the internet, so attackers may be able to access the decrypted state that way. To guard against that, you may wish to encrypt certain documents with an additional password, even if they are sitting on an encrypted file system.
Recall that within a month, the widely SSH was exploited and a backdoor added to every machine. I had upgraded to that SSH version. I didn’t run an SSH server on that box, but it goes to show that even those who take precautions can end up exploited!