I've used Tor for a very brief period once in my life, and that was to purchase adderall off of either Silk Road or AlphaBay (I can't remember), and I'm unsure of what the Tor ecosystem is like today, but not even that long ago, the vast majority of the Tor network was used for crime - ranging from child pornography, to hitmen available for hire, banned weapons, and obviously, for drugs.
I did not come across anything meaningful browsing the onion ecosystem, but left with a depressing insight of anonymity.
On a higher level pov, anonymity allows some of the most toxic and damaging ideas to brew and fester.
This is easily pointed out by the characteristics and behaviors between Twitter accounts that have an association with a real individual as opposed to ones that don't.
The difference in what they tweet is staggering.
Not to mention sites like 4chan and it's children.
Don't get me wrong, I'm rather against Big Brother or ISPs tracking and selling off our data, but absolute full anonymity is just an invitation for some of the worst things to happen.