Two quick hits:

(1) It's important to remember that part of why Telegram is in this pickle is that they deliberately designed a system that increased the surface area of what governments could demand from them, because they're not fully (or even mostly) end-to-end encrypted (in fact, they were openly dismissive of end-to-end encryption). We get these kinds of interventions in part because governments know they can work; we know how to design systems where they can't work.

(2) The idea that governments worldwide will uniformly solve this through international agreements seems fallacious, because some of the largest countries in the world have sharply different legal and political standards. For an agreement on lawful intercept to work, you need to foreclose on products that refuse lawful intercept. There are countries you can do that in, and others where you can't.

I think there is a well-taken point that cutting off law enforcement access to data isn't a long-term stable equilibrium; something will give eventually. But I think PHK is way overshooting how strong that argument is today.