Ironically, making changes like this makes you far, far more fingerprintable, as the vast majority of users don't make changes like this. Thus, the users that do stick out like a sore thumb. The article does mention this.
Canvas/WebGL fingerprinting is a good example of this. Yes, very few people block it, but the fingerprinting for canvas is so individualized to each device that there is no hiding in the crowd if you leave it enabled. You're hiding in a crowd of size 1.
Think of it like wearing gloves during the summer. Yes, that's unusual. But a human fingerprint (except in rare-ish cases) will usually be good enough to track an individual person. In a world where people are regularly collecting fingerprints or tracking them around town to figure out who's been in what stores, being unusual is preferable to being unique.
There are a few settings (normalizing screen sizes) where the benefits aren't so clear-cut. But at the very, very least, you should be doing stuff like turning off webRTC/webGL/canvas. The majority of changes being listed here are strict improvements to privacy.
Long answer, I'm also curious about this. I feel like the future of fingerprinting resistance isn't refusing to give up information (since sites can block you or force you to turn the settings back on) -- it's lying. Don't block microphone access, just feed it white noise. Don't block the location, just spoof it.
BUT, a bunch of people who are smarter than me have decided that zeroing out the canvas is better than making it return random values, so for the moment, I assume there's something they know that I don't.
WebGL fingerprinting, in my investigation, seems to be identifiable by gpu vendor, and potentially by generation, but not individual GPU.
So there's still bits of info, but not as bad as they used to be, or as bad as people generally fear.
Any chance you could point me to a source on this?
You're confusing privacy and anonymity. They can be mutually exclusive.
Improving anonymity is reducing the odds that data can uniquely identify you. Making changes to Firefox harms anonymity because very few people deviate from defaults.
For example, turning off Javascript prevents a site from knowing much at all except header information like User-Agent. So it can't draw a canvas fingerprint nor measure your screen resolution, but it can still record the fact Javascript was disabled - a rare event.
OP is correct: the changes make one 'stick out like a sore thumb'; but incorrect in asserting users are 'more fingerprintable'. Improving privacy may reduce anonymity, but losing anonymity does not necessarily affect privacy.
While anonymity and privacy are theoretically separate concepts, many current techniques used to compromise privacy on the internet are dependent on de-anonymization.
None of the data your browser leaks is being used to directly compromise privacy. Your screen resolution, user-agent, canvas fingerprints, etc aren't private information. Their only utility is to support de-anonymization, which in turn allows a compromise in privacy by aggregating your behavior.