It was the late 90s, social media platforms like Facebook didn't yet exist, texting was in its infancy, email was very popular, instant messaging was up for...
The bottom of the article links to the history (individual features) of other IM programs from that era as well like ICQ and Yahoo Messenger.
I think once SMS and phone apps became the norm over having Messenger apps on our Desktops all the time, that was pretty much it for these applications over all. It was a long, slow death. But MSN was one of the firsts to call it quits if I recall right. Oddly the IM app I liked the most. It's just not many of my friends used it. They were all AIM/AOL users.
The one thing these messengers had over texts was presence notifications. I remember jumping through hoops to get aim working on my Motorola v188 so that I could be notified every time my crush came online and I could send her a “hey what’s going on”… only for it to be ignored.
With Linux and other FOSS projects surging in popularity, I dare say we’re in for another.
But, sadly, companies don’t seem too interested in making good software for that sake of it being good anymore. Now it’s all about getting you hooked on an eternal subscription.