As stated 3rd party actor breaching/hacking government is guaranteed!
Another factor if money which is not on the individual side, but on a state actors (i.e. China will focus all to get there and per history it will get there).
In addition chance of "the beast" finding a method to break any new end2end encryption is likely/tbd/time, however individuals/open-source shall be finding another new method over night :-) as I ~40 years ago on 8bit computers I made very similar algorithm to Rijndael AES and I was a kid and that was ~20 years before AES was invented!
So will I have to shut down my personal Nextcloud and Matrix server? Also what will happen to SSH? it's also E2EE