disvor

Linux has a richer set of security features available than OpenBSD, in some areas.

One is the mandatory access control of SELinux, used extensively in Android (probably the most widely-used Linux distribution of them all). This has no OpenBSD equivalent, as far as I know.

Another is that the Linux kernel has some compiled-in exploit mitigations enabled that OpenBSD doesn't, such as automatic bounds checks on fixed-size array access (based on UBSan).

It protects against data being directly copied off the disk by anyone who may have physical access to the machine, but who lacks credentials to log in.

Is there any support in OpenBSD for storing key material in a TPM?

Windows has this, and it permits booting without a passphrase being entered, but the disk will still be encrypted at rest.