DivestOS is the most thoroughly degoogled of the android ROMs (it removes the most proprietary binary blobs). DivestOS is also decently security hardened, better security hardening than any other Android ROM other than GrapheneOS. But since it removes more of these proprietary blobs, it further reduces the attack surface of the ROM. Both GOS and DivestOS are good options. As commented by another user, /e/OS falls behind on security updates often, which is quite bad for a security or privacy focused OS.