OpenBSD (and it’s subprojects) are highly secure, moreso than Linux.

I highly doubt that OpenBSD is more secure than Qubes OS or secureblue.

KeePassXC 2.7.9 was released before the statement

An alternative is the old version of KeePassXC.

firejail

I would recommend not touching Firejail unless you are 100% sure you know what you are doing, as it can (and probably will) worsen security.

This whole document is a bunch of outdated information, misinformation and manipulation.

The XLibre project continues this legacy with active community development.

This particular part shows the real reason why it was written. Go promote your Nazi-maintained nonsense somewhere else.