Like it or not, we are in the military, a professional force that is not one of first-name basis, and we have identifiers for various things, rank included. Whether they are high vis or not is to me immaterial, because if there's a need to subdue that rank, then we will. As for us, here in Canada, where we now as a habit wear our field uniforms in office and garrison environments, we would have to accept that we wear rank that can be seen. Yes, we all know our COs, RSMs, etc, but we wear our rank not for those who know us, but those who don't. And our rank is a visible sign to others that rightly or wrongly is used to allow others to gauge us in terms of authority, competence, etc.
As for an historical example of an army subduing or altering its rank insignia for "practical reasons" (eg: combat), look no further than the Waffen SS. Here is a chart of their insignia
The insignia in green is what they ended up wearing on their field camouflage uniforms, as can be seen in this war-art:
We talked about field units, in combat, etc. The Waffen SS was an organisation that was, among many traits, resourceful when it came to surviving, especially on the Eastern Front.
So, it may be nice and equitable and all to forget that we have ranks, and some may like to go by first names, but as a professional army, we ought not to make it a habit.
:2c: