[isatty]

It just works. You may think that this is a meme, but it really is not. Let’s say you and someone else that you wish to communicate with has an iPhone (parent, SO, friend, whoever) and things just click into place.

- Extremely responsive, native, fast app with no clutter whatsoever, on both phones and on desktop devices (personally, I highly dislike web/electron apps)

- Close to no spam (whatsapp in particular seems to have a ton, way worse than Telegram even)

- Highest quality (amongst all the apps) audio/video calls with Facetime

- e2e encrypted by default, does not have the unconscious bias that you’re using a Facebook owned product for doing something secure, even if it really is (and as far as power users go, I don’t really particularly dislike the company like many do)

My next favorite messenger, that does Groups better than iMessage, is Telegram. I don’t wish to get into the privacy concerns (and it’s valid!) but as far as making a responsive, native app that does chat and does it well, it’s pretty superior to both Whatsapp and Signal.

gTalk of old was amazing, but I don’t think that’s coming back :(

[troupo]

That "no clutter whatsoever" results in every action requiring two-three more clicks than necessary.

As for "fast", just the animation in the main action menu would like a word. And then try to select stickers

[jwells89]

It working well on desktop is a big one. The only other messenger that comes close (that I’ve tried anyway; haven’t had a need to use WhatsApp for example) on that front is Telegram, which not only has a Qt-based client that’s decent everywhere but several native clients (Swift/AppKit/UIKit client on macOS on iOS, UWP client on Windows, GTK client for GTK desktops on Linux, etc).

Signal could be like Telegram in this regard but its hardline no third party client policy means the official Electron app is the only option.

[bobbylarrybobby]

Don't forget one of its best selling points (especially in the US in ~2010): phone numbers as IDs. Everyone has a phone number, and your friends all know yours and you know theirs. It is the least common denominator of all digital communication. This really reduces friction compared to, say, having to share a username.