Because they didn't support E2EE and homomorphic encryption.

"An investigation by ProPublica found online pharmacies that sell abortion medication such as mifepristone and misoprostol are sharing sensitive data, including users' web addresses, relative location, and search data, with Google and other third-party sites — which allows the data to be recoverable through law enforcement requests."

"we also know that social media isn't likely to stand up to illegitimate law enforcement requests, because of the fact that they fear their own liability, or because of the fact that it's just too costly to stand up."