Signal has the most carefully designed cryptographic protocols that you can run on a central platform, thanks to Trevor and Moxie. They have truly inspired many end-to-end encryption advances everywhere in the last decade. Great stuff.
However, Signal depends on Amazon/ DynamoDB, Intel/SGX , on Cloudflare, on Google Cloud ... and operations are expensive, with financing dependent on US jurisdiction and non-profit status there.
Dear @Mer__edith , isn't it time to revisit operational choices?