New sidebar/navbar icons are not better
I like that we're starting to create our own icons, since the ones we picked from fontawesome often didn't make much sense (Merge Requests being the prime example).
However, I think we should only switch to our own icons if they are a clear improvement, which I don't think is the case for the new icons for Project, Activity, Pipelines, Merge Requests and Groups (see the screenshots below). The current icons don't make much sense either, but at least we're used to them. Changing them for the sake of change will create more confusion than it will remove.
On top of that, the new icons seem to be a lot heavier than the fontawesome ones. Thicker lines, and less definition. They look out of place