$5 wrench would always know the exact sum you possess.
Joke's on them - I don't even know the exact sum of bitcoin I own. 
If you deal with the excessive amount of crypto all your data are already in databases of the various 3-letters agencies
Well, this is true if you complete KYC at centralized exchanges which hand your details over to your government, if you continuously reuse all your addresses, if you link all your coins together through poor privacy practices, if you do all this without using Tor, and so on. If, on the other hand, you only trade peer-to-peer, you never complete KYC, you never link to your real identity, you always use Tor, you always mix/coinjoin your coins, you never link inputs from different places, and so on, then the chances of your details being in a database somewhere are far smaller, let alone someone being able to accurately link all your holdings together. Sure, if you started doing a bunch of illegal stuff and became a specific target for a three letter agency then I do not doubt they would be able to track down you and your coins, but it is entirely possible to avoid the mass surveillance of the general population that most governments partake in. It's neither easy nor convenient, but it is doable if you are motivated to do so.