Here is what I don't understand: Let's say I as a private individual fund 1000 tor nodes (guard and exit nodes included) and have them all log everything. This could cost less than $5000 for a month, with some time needed to get guard node status. I want to find a certain kind of person so I look for people that access a specific hidden service or clearnet url. Surely eventually I'm going to get a hit where all three…
Using Tor, like all security and privacy tools, must be balanced against what it is being used for. We will always live in a world of limited resources for policing, and systems of privacy work by increasing the difficulty and cost to deanonymize someone. They don't have to be perfect, they just have to be expensive. If you want basic anonymity while researching someone powerful or accessing information, it's extreme…
Take for example, John Draper who discovered in the 60's that a Captain Crunch whistle toy could be used to make free phone calls on the telephone systems. Or the discovery of Side Channel attacks by an engineer at Bell Telephone company who noticed that a Bell Telephone model 131-B2 would produce distinct spikes for each key pressed on the oscilloscope across the room. Therefore not requiring nation station level expense to break the encryption used by Navy and Army's encryption systems. Or during the Afghan war, the US was deploying armored vehicles that they assumed would provide good protection, and would be expensive to attack by the enemy. Turned out they could make IEDs from inverted copper cheaply and within locals kitchens. That proved very successful. Or the kid who discovered he could bypass the mint screensaver by smashing random keys on the keyboard (https://github.com/linuxmint/cinnamon-screensaver/issues/354). The list of these types of cheap attacks are throughout history.