e2e encryption is mostly moot considering neither the client-application nor -device are really trustworthy.

then there is the problem with push-notifications passing throu either google or apple as well as device-backups which both hand over your metadata and probably message content.

imo telegram is in a better spot simply because it is not affilliated with the facebook/google ecosystem but in the end it does not make much of a difference due to aforementioned systematic deficiencies.

imo good reasons to cash in on the platform compatibility and convenience of telegrams cloud-messaging architecture.