Compare https://en.wikipedia.org/wiki/IBM_Notes#History from 1989 with roots going back to 1973.
So what will GOV.UK Notify do?
Government receives millions of calls every year, from people anxious to find out where their thing is at. People have to spend time on hold, and running call centres costs a lot of money.
GOV.UK Notify is going to make it easy to keep people informed, by allowing service teams across government to send text messages, emails or letters to their users, before they get anxious enough to call.