The "no icons" falsehood was propogated by an elitist faction of IL2 that proclaimed that anybody flying with icons is cheating, a lesser pilot, holds their manhood cheap compared to those that use "no icons" and so forth.
It's a blatant lie and basically just ego-stroking.
We have had discussions on these very forums before detailing the science of optics, distances and details visible at those distances. We have referenced real life air traffic personnel at airports, commercial, private, and military pilots, we have referenced anecdotal WW2 reports of being able to ID planes at distances using the fuselage codes and all of these details.
What we can see in-game is a joke compared to reality. It's nice, but it's not REALISTIC. The icons make up for a massive loss of detail that would equate to all players in this game playing like legally BLIND pilots in real life. They never would have been able to get pilots licenses at any point with eyesight like this game portrays. There are many reasons for that: including pixel dots, sizes, the need to have a wider FOV for rendering screens and depictions. The icons make up for that.
Removing the icons doesn't help gameplay at all, despite what the AvA crowd tried to push for so long. It hurts gameplay. In every respect from WW1 onwards, BFM have been a part of dogfighting. Before-Fight-Maneuvers. The posturing and positioning you undertake to get an advantage on your opponent BEFORE you're in lethal kill range. It's a massive part of air combat, and with no icons you literally cannot even determine a very rudimentary shape, range, or even orientation and angle of an enemy plane until it's already inside kill range.
No icons leads to unaware picks, simulating legally blind pilots and/or the baby seal clubbing effect. That's the only true reason to ever demand/request it be forced on everyone. The demander/requester wants easier kills for their own benefit.