I was working on exactly this many years ago at the OFTN OSWG with an open source project called Hum.
I stopped development after Apple got sued for secure p2p video chat with the original version of FaceTime, seeing as Hum was also going to support secure multiparty p2p video chat. Unfortunately VirnetX (and by extension, the US military) owns a patent that would have made deployment of Hum difficult without an expensive legal team.
It's not too hard to imagine that the real reason you don't see many p2p encrypted communication platforms is US military-sponsored patent trolling. This aligns with their mass surveillance interests.
The person is wrong. It's a private company that has the patent, the company works with the government. I don't know why he implies the government is involved in the patent suit, they are not.
"It's not too hard to imagine…" isn't exactly the same as saying "It's true that…". I don't have hard evidence, but it's not hard to imagine VirnetX being manipulated behind the scenes by the US government. Similar circumstances have happened in the past.
The Ars Technica article on their lawsuit against Apple [1] said they advertised a product on their website but received zero revenue from that product and seemingly didn't have any engineers working on it.
The latter being more charitable because it also answers the first question and can assume the asker at least has a semblance of why it might be possible.
Such a due diligence requirement would not be compatible with the current patent system, you are unlikely to be doing anything these days without infringing on someones patent.
I stopped development after Apple got sued for secure p2p video chat with the original version of FaceTime, seeing as Hum was also going to support secure multiparty p2p video chat. Unfortunately VirnetX (and by extension, the US military) owns a patent that would have made deployment of Hum difficult without an expensive legal team.
It's not too hard to imagine that the real reason you don't see many p2p encrypted communication platforms is US military-sponsored patent trolling. This aligns with their mass surveillance interests.