From engineering users perspective.

It's primarily used for commissioning, controlling project progress for PMs, and accessing Work Orders for each project.

Gathering all the works with the date of service in one place, I guess that's the most helpful solution for Project managers.

I don't know about the past. I can't speak with 100% certainty about the past, since I wasn't working in this field, but from what I've heard from my manager and colleagues, things are getting much easier with Maximo.