right, a lot of features are incompatible with E2EE as a concept and also for groups... how the fuck you gonna do E2EE with a group that can have 200,000 members?

To do it right you need to re-encrypt the same message for each member of the group. Suddenly your 1MB gif becomes 200,000MBs that need to be uploaded? (alternatively you upload the image only once but it's encrypted with a unique key, then distribute the *key* to each user -- but still needs to be encrypted with their own pubkey, so it's less data but still insane)