We recently on-boarded a new customer that is still on CRM 4. That's not a typo - that's the last version before CRM 2011. It was originally released back in 2007, more than a decade ago, which is like a century or two in technology time. CRM 4.0 came out just a month or two after the original iPhone was released and a full year before the Global Financial Crisis.
Anyway, as we were learning the intricacies of this system, some of our "fresher" Dynamics 365 consultants who have never seen this ancient system commented on how similar the UI is to the new Unified Interface. At first I didn't see it - I worked with CRM 4.0 for years and couldn't see past the non-customisable blue theme.
After talking it over, we realised there are two main areas currently in the Unified Interface which were in CRM 4.0, but were gone for a long time in whats now known as the Classic UI.
The sidebar
In the Classic UI many users have grown accustomed to navigating the system from the top:
This is actually the second iteration of this top navigation with the first requiring multiple clicks to first choose an area, then open the sections for the area. The change came in an update to CRM 2015.
As part of the Unified Interface the navigation moved to the side. Initially we had a set of icons \ shortcuts which were always visible, and we could get the full site map with a single click.
But look how similar the CRM 4.0 sidebar and the current Unified Interface navigation. They are both on the left of the screen, have the different areas at the bottom, sections are similar with a title and similar icon and text seizes for each entry. They are similar in size, personalization options, and more.
Form Tabs
The other feature that made a comeback is the Tabs. From CRM 1.2 all the way to 4.0 we had tabs on record forms:
Then in CRM 2011 that changed. The official word was that tabs became horizontal, but for many the tabs were just gone. All fields\content was on a single page and you could simply scroll through the entire page; the "tabs" were just shortcuts to places on the form.
Various customizations were created to try and change this and go back to CRM 4.0 style tabs.
And now, with the Unified Interface, tabs are finally back:
Conclusion
I'm not sure if we really have a conclusion from this. Perhaps that User Interface is created based on current design patterns and "fashion"? Maybe that the CRM 4.0 UI was actually good? Or maybe best practices come and go in waves, like many other things, and simple make a comeback every decade or two.
I think the lesson is that sometimes we make changes just for the sake of change, without thinking are we making it better or worse - we just want something different. Sometimes you need to lose simple navigation just to appreciate it more when you get it back.