Yes encryption means security but not this time.
Encrypted DNS doesn't harden your security in any way like DNSSEC or certificate pinning does for example.
Encrypted DNS "only" increase your privacy against "man in the middle".
I also doesn't say it's not needed as I use always encrypted DNS, but it's not what most people think it is.
You can read more at
GrapheneOS Frequently Asked Questions (not GrapheneOS related)