I'm surprised Google Duo hasn't become more popular. It's a great cross-platform video chat app. I especially like the feature where you can see the other party before you answer their call. I have taken calls because of that feature that I otherwise wouldn't have. It's better than FaceTime because it works on Android. It's better than Skype and Google Hangouts because your cellphone number is your identity; you don'…
For apps that rely on network effects, pure feature competition isn't the only (or sadly, even the most) relevant factor. I commented on this in the Duo announcement thread (https://news.ycombinator.com/item?id=12295847), but the gist was something like:
With GChat, they squandered a massive, decade-early networks effect advantage with ten years of inexplicably idiotic product decisions, rebranding, failure to adequately replace deprecated products, etc. I actually generally consider them to have the absolute best products in terms of feature quality, far more often than not; Yet at this point, I can't imagine why anyone would see a Google product that relies on network effects at all and not run as far away as fast as possible.