I had this same issue when I started IL2. I found that if I stayed low it was much easier to see them against the sky then the ground for sure. I also had to get used to IDing the planes and sometimes got to close and lost all my advantage by the time I figured out it was a bad guy.
I also learned that it's tough to ID a plane from dead 6 until you get too close. Since then I've tried to dive down lower on their 6 to get a better silhouette to help with ID. Not sure if that's the same in DCS but I found that to be my biggest challenge in IL2 in VR.
I have had and still have that argument with DCS guys today. We've had this argument in sims for 30 years.
Any DCS server I setup will always have labels\icons enabled to some extent. maybe in 20 years when technology advances to the point where there is no difference to resolution and HDR compared to the eye of a 20 year old WWII pilot, then drop labels\icons. Until then, the result is actually less realistic than not having icons.
DCS supports them, but they are not as nicely implemented as AH's.
I think some of their bais comes from modern jet experience where you have electronic IFF and being vectored in by AWACs that have already identified type and range and bearing. Or in helo where you are so low and slow and usually looking at a target in a magnified MFD screen so icons are not as needed.
Warbirds need them IMHO. It leasd to better gameplay.