CalyxOS is not hardened in any way and is in some ways less secure than stock AOSP. They are also on a hiatus and have discontinued updates: https://discuss.grapheneos.org/d/24791-departure-of-calyx-calyxos-leadership-and-discontinuation-of-calyxos-updates

LineageOS also significantly regresses security compared to barebones AOSP.

• Userdebug builds
• No locked bootloader or verified boot
• Incomplete backports of patches