They do tend to represent ideas like anti-censorship, individualism, and (sometimes) privacy. I think it makes more sense to discuss these topics in terms of the actual implication of what you're decentralizing, and how it actually helps.
For example, the Internet itself is decentralized. But from the perspective of your particular ISP, it's not at all decentralized (if your ISP turns off your Internet, it's game over).
Email is also decentralized, but so what? Most people use the same email providers so it's somewhat meaningless for SMTP itself to be decentralized. Google can still read your emails.
The problem with using these terms instead of more tangible language (i.e., language that describes what the thing is actually doing) is that they tend to get hijacked by scammers/marketers who just want to harness their popularity for their own ends.