I can answer that: it’s the “I don’t care about security as long as I can send memes and inappropriate messages to most people” experience.
From the looks of it, it’s as secure as having WhatsApp/Signal/Telegram/ProtonMail doing “E2EE” through each app’s servers, and never knowing whether the client did the encryption right, or if it sent the keys to the server for messages to get intercepted… well, except you do know that the bridges are decrypting all messages anyway.