Telegram is completely cloud based. So all your conversations, except secret chats that are end-to-end encrypted, are stored on Telegram servers in plain text for as long as your account is active. This is why you can get a new device, activate it for your account and get all your conversations back on it from the Telegram servers.
Wire and Signal work differently. They use their servers as a temporary storage to hold your messages until the recipient comes online and then deliver them. Wire also retains the messages for a few days to allow delivery to multiple devices that a user may be using, with each device possibly coming online at different times. Signal doesn't have to support this because it's tied only to a single device, which is your phone.
The Git usage was really nice. It's fast and secure. While I didn't use it for most projects (because I want them on github/gitlab for various reasons), it was very useful for backing up machine specific configs and history (using a script and mackup). Knowing that it was well encrypted made me not worry about what was being backed up, if there were credentials, etc.
As for comms, I used the 1:1 chat with a friend for quite a while. While it worked, it's slow. Sending messages is a little slow, sending images is VERY slow. Anytime the app is closed (like constantly on the phone), re-open times were slow (for decryption). Eventually I gave it up and moved those few chats over to Telegram (Because it's secure enough for most conversations).