It exists because FSF. (watch Linus's opinion on FSF) Unfortunately the FSF is full of obsessive people, who want politics to be an if-else problem. But that's not how politics work, you always have to compromise somewhere. You cannot have hardware that uses open-source firmware, has schematics available, doesn't use slave labor, is usable, is secure etc. You always have to choose between different evils.

But that's not what the FSF does. They decided to draw a thick line through this blurry mess, so that these obsessive coders can have a digital high/low solution to this analog problem.

hm how do I continue...? It's hard to explain because it does really make sense but I will try. So if some software runs on your computer and you can modify it from the OS, it has to be Open Source otherwise it's not FSF big wholesum chungus certified. But if it runs on your PC and you cannot modify it from the OS, it can be closed source and still get the Chungus certification. What you end up with is that FSF recommends some old crap wifi cards running proprietary firmware because you cannot modify the firmware without external flashing. But it rules out new wifi cards that load the firmware during boot because the linux kernel cannot have proprietary software in it reeee. Obviously the latter situation is better for freedom because it's at least easier to replace with Free firmware but they don't care about that.

In other words Linux Libre exists only because of some stupid bureaucratic rule that actually harms Free Software instead of helping it.

Wait I haven't told you about microcode updates! Microcode is proprietary software controlling your x86-64 CPU. Linux Libre does not include updates to this firmware even though the microcode is proprietary regardless. So with Linux Libre your CPU is controlled by code that is proprietary, broken and vulnerable to stuff like Spectre or Meltdown. This part is so stupid that it's almost funny. (but it's actually sad)