It's nonsensical to talk about solutions if discussion of the problems is off-topic.
I hate to say this but I came to the conclusion some time ago that "see and be seen" is largely a myth. Because of the natural limitations of the eye, the main reason that there are so few mid-air collisions is because the air is such a big place and there are, relatively, so few aircraft flying in it
This is true; as you probably know there's been a lot of proper research done that confirms your view. Theoretical studies. Practical experiments with 2 aircraft where they sit a pilot as a passenger, and fly the second aircraft around and ask the pilot-passengers to record when they see it. All of it confirms what you say: a good lookout only slightly reduces your chance of a midair collision because you don't see most traffic.
My own view is that a good lookout remains helpful around airfields where you can predict - more or less - what paths the aircraft are going to take. That means you can focus your attention on the most dangerous regions.
As for the number of near-misses - I'm not particularly impressed. As the numbers of mid-air collisions are low, anybody trying to study them will do well to look at near-misses, which are more frequent. For example, if there were to be lots of near-misses in the Luton/Stanstead corridor this would be a good indicator that something ought to be done to prevent a future accident. However, if you say 'it's true that over a period of X years, mid-air collisions make up only Y percent of fatal accidents - but look how common near misses are', this doesn't make mid-air collisions any more of a risk.
It's true that midair accidents are often fatal when they happen, but even then they are infrequent enough to be rare causes of fatalities. The issue with yet another box of tricks is that it's potentially yet another thing to distract our attention from the important things in aviation.
This isn't to say that I'm against the idea. If the signal to noise ratio is low enough - i.e. it only distracts you when evasive action is actually required - then why not? And in the future I think we will need tools to enable us to share airspace with drones.
I think part of the reason mid-airs capture our imagination so much is that psychologically we like to think we can handle emergencies such as an engine failure or inadvertent IMC - even when this may not be the case. The idea of colliding with another aircraft then being a passenger all the way down though, is horrifying.