20 years ago there were a bunch of half-baked OSes that had very narrow hardware support, little to no security models, and horrible developer ergonomics that made doing native GUI Linux apps seem easy by comparison. It's actually good that these died out.
Are you sure about BeOS? Half baked? If any, the half-baked OS in that era was Linux. Until the 2.4 kernel it sucked having several sound daemons. BSD's got it right at least.
Haiku OS didn't die, and the day it gets hardware accelerated GL/Vulkan support (now it's done thru MESA/Lavapipe/LLVMpipe), we'll talk about which os is thruly half-baked.
On security, your sensitive data belongs to an unprivileged user, do unless you set your perms to ugo+r/ chattr +i to your sensitive files, you are screwed in the same way.
Yes, OpenBSD has unveil/pledge, but it's still dangerous.
You can set another user account for that, sure, but the most correct to handle that is to set that data in external media and access it on demand.
