Windows had barely landed. Networking was really only used for file serving in most corporations. There was no email at most companies and TCP/IP was still mostly a university and government thing.
Notes turned up as a deeply sophisticated Windows application, a no-code development environment, document oriented, replicated distributed shared data system with built in security encryption, email and all deeply integrated with the concepts of people and groups of people, which everyone takes for granted now, but back then wasn’t part of corporate computing at all.
The email alone led the rise of Lotus Notes, let alone the rest of the system.
Using Notes you could suddenly create applications that shared data across your office locations - you ran a server locally and Notes dialed up the other servers and did replication of just the changed/different data. It was gob smacking because nothing else could do this.
At a time when personal computing was very much the model, it was like someone had sent this software from the future.