Tor is an anonymity service that can be used to anonymously browse the Internet (whether on the clear/surface web or the dark web) by means of the free and open-source Tor browser.
Tor was created by the US government for some reason that will benefit them
Tor developers (some of them) work closely with government agencies
Everyone will know that you are using Tor (but not what you are doing)
Malicious exit nodes can listen to all traffic on non-HTTPS websites
Strong adversaries can probalistically determine which Tor user is visiting a website by "timing attacks" (that is, getting the times a packet of data passed through an entry node and exit node which are controlled or compromised by the same adversary)
Tor is (still) being funded by the US government and Big Tech corporations
Tor is also being used by the US government, and ordinary users only help mask their activity
Regardless of the reasons stated above, I personally still trust Tor for the following reasons:
Its encryption has not been broken (yet)
Most (if not all) Tor users already know that the US Navy started Tor
More and more of its previous vulnerabilities have been patched up, meaning it gets better over time
Timing attacks are mostly inaccurate, especially when there are more people using Tor at the same time
Tor hidden services are always fully encrypted on transit, so there is no need for SSL/TLS encryption
