I've been documenting and training ERP systems for 7 years.

The Navigation Pane is the easiest training format to introduce new users, where they can flip from one option to another, setup favourites and generally get a feel for what's available on the system.

Removing the Navigation Pane makes access slower, because searching is slower than clicking on a favourite link.

Oracle Fusion gives you the option of both with or without a Navigation Pane....in my experience users choose with. They like a roadmap.

I appreciate that if you are working from a tablet or smart phone that space is a premium, but most users working with ERP do so from a desk monitor or laptop. Hence the option to have it or not, rather than removing the Navigation Pane completely.

.....and while I'm asking, is there any chance of bringing back the "grid" search line, it used to be triggered CTRL g. This was the biggest loss when AX changed to D365, slowing down multiple filter setup.
Creating and saving searches (views) was a lot faster in AX.

Kind regards
Andrea