Why would someone do that if they know the faked degrees or qualifications won't pass the background check eventually? Just to get an onsite interview?

Yes, just to get an onsite interview. I saw this many times and it's very sad.

Also, I relate this to culture. Not to offend anyone, but from my personal experience lying in CV is much more common for some countries, that for others.

Scale maybe terrible, like multiple certifications in some field with no actual basic knowledge or skills. Like Certified Senior (sic!) Software Developer who can't tell you difference between stack and queue, or CCIE certified network engineer who has no idea what is DNS and how it works (real case).

And what makes it different for those people without anonymous recruiting?

As soon as I walk in the door I will be eliminated. But how can you interview someone without actually seeing/talking with them? Slack? Would anyone hire based only on a Slack interview?

Even if you get hired, you still have to show up for work and can be fired later due to the same bias.

If both the application and the work is completely remote and anonymous it might be possible to avoid most bias, but that's only feasible in IT and a couple other sectors and even there it's not common.

No, firing people is more expensive than rejecting them. And a lot of bias happening in the recruiting process are unconscious. So anonymous recruiting would prevent a lot those unconscious bias in the hiring process.

In most jurisdictions it's hard to hard someone. In all jurisdictions it's expensive.