So just another point on this… you are probably not as anonymous on the internet as you might think. You can brag about wealth in cryptocurrency. But use a handle long enough, or even across several accounts that can somehow be linked, and a fingerprint of you could be constructed. It really can be done with some forensic analysis.
And I think it all boils down to the fact that some humans need to make noise about their successes so they feel validated. Much like the cryptocurrency evangelists, they probably can’t help themselves because they want to ensure they defend “the mission” even if it comes at great personal cost in the long run.