You really ask why? This isn't about serving justice - it's statuary example for anyone trying to run an unmoderated platform.
If you are alleging that there's comparable, specific and actual legal infringements on the part of meta/google, that somehow go uninvestigated and unpunished, free free to point to that.
The only E2EE in Telegram is called "secret chats" and they're 1-on-1.
i don’t think messaging startups should be required to employ hundreds of people to read messages
It was their decision to become something bigger than a simple messaging app by adding channels and group chats with tons of participants. It was also their decision to understaff content moderation team.
Sometimes the consequence is a legal action, like the one we're seeing right now. All this could have been easily avoided if they had E2EE or enough people to review reported content and remove it when necessary.
Even E2EE messaging service providers have to cooperate in terms of providing communication metadata and responding to takedown requests. Ignoring law enforcement lands you in a lot of shit everywhere, in Russia you'll just be landing out of a window.
These laws have applied for decades in some shape or form in pretty much all countries, so it shouldn't come as a surprise.
But i have no idea if it truly has more or less crime than other platforms. So we can't really tell if he's being messed with because he can't stand up for himself in a way Microsoft or Musk can, or it is truly a criminal problem.