And I am curious, and wanna ask, how does one invest in crypto anonymously? Can one invest in bitcoin without going through a centralized exchange or p2p trade through uniJoin? If yes, how does it work?
It's in the why unijoin page:

There are risk in using the same address and store funds within the same wallet even if you buy from true p2p or BATMs or if you use the funded address to directly deposit to something that requires KYC.
So if I buy anonymously each month 1000 euros of BTC from someone, that guy still knows that how much I bought and my bank number and can even know when I'm buying coins from somebody else or where I move my coins, same from a BATM that takes a mug shot of you when you use it, they know the address you have received funds from there your identity is linked to that.
An example how things could go wrong would be simply buying from guy in person coins and he sees that you store the coins in a 50BTC worth wallet, would you meet with a stranger that can track and know you have $2 million worth of BTC?
Now if that stranger is a police officer?
And funny thing, I like how they used the map of China there!