That is not a problem for open source that has been audited.
We also know why the US government supports Tor: It goes against geopolitical adversaries like Iran and Cuba by helping dissidents in their countries.
Their activity. Not yours. https://www.theguardian.com/world/2013/oct/04/tor-attacks-ns... https://edri.org/our-work/secret-documents-reveal-bnd-attack...
Big leap of faith. You probably won't need both hands to enumerate people capable of correctly audit a piece of modern crypto software in the hole world, and probably half of them work or have worked for governments. Even using those resources, one thing are obvious flaws, other are weakening of the robustness of the protocol in certain conditions. Even with your top 5 (first hand), no one would guarantee the protocol and implementation is free of backdoors.
> We also know why the US government supports Tor: It goes against geopolitical adversaries like Iran and Cuba by helping dissidents in their countries.
I'm not a tor expert by far, and even I know that if you have enough entry and exit nodes under your control, you can identify both source and target of traffic. It makes sense for the USA to use a communist/Iran(terrorists!) excuse to pursue that goal. So, it makes sense to create a layered secure communication channel that only you can reverse, and pitch it worldwide as a safe means of communication for "dissidents".