Fair point. There is temporary obfuscation, and certainly not end to end encryption when torrenting.
The creator of BitTorrent himself has this to say:
“The so-called ‘encryption’ of BitTorrent traffic isn’t really encryption, it’s obfuscation. It provides no anonymity whatsoever, and only temporarily evades traffic shaping. There are better approaches to obfuscation, and I’ve got a great team of engineers who are quite eager to fight that battle, but I’m hoping that everything can be resolved amicably without getting into a serious arms race.” Source: torrentfreak.com/interview-with-bram-cohen-the-in…
In my opinion using a trusted VPN not just for torrenting, but also for sourcing pirated software or other content is just a best practice.