I don't think many pilots fly with their head
inside the cockpit - unless they are in IMC.
And the more automation one has e.g. an autopilot the more likely one is going to be looking outside.
I am sure I have had near misses with other planes who took avoiding action, and they cursed me blindly as yet another stupid pilot with his head inside the cockpit and playing with his knobs
The truth is that I was looking out about 99% of the time, and didn't see them.
The UK treatment of IMC/IFR/VMC/VFR is indeed odd, but it does rather suit the powers in charge because it absolves them from having to provide an ATS service in Class G!
Currently, there is no ATS service in Class G - there are just bits of LARS when one can get them. The IFR/airways traffic gets a proper service, as they do everywhere else in Europe, but below the airways there is an absolute watertight cutoff.
If we were to get a universal enroute service (I mean radar, obviously) in Class G, somebody would have to pay for it, and nobody wants to. And, to be honest, I am sure that if you lined up 100 GA pilots and gave them the choice, 99 of them would prefer to fly for free and be on their own. Like me, they are happy to fly under their own nav, using GPS, and keeping out of everybody's way. With their transponder on Mode C of course, for the benefit of anybody who has spent the money on TCAS.