I've tinkered with Telegram for years, but really dove in over a year ago when I grew tired of Skype for Business failing, Slack feeling too cumbersome, Google not having their act together with...well pretty much anything to do with messaging, and FB/WhatsApp being too ominous/stigmatized.
I have used Telegram on iOS, Android, Chrome (browser & OS), and Windows. It just works. If I could get everyone I chat with to use it instead of one of all the other ones, that would be a refreshing change.
The one app that has an advantage over it is GroupMe because of SMS mode. A person can opt into receiving and sending messages via SMS only. They lose a lot of functionality, but it's still possible and works well.
I love Telegram and use it as my daily work messenger. It's blazing fast, reliable, and works pretty much perfectly. My only wish is that they would support SMS so I can ditch my other messaging apps.