wf
Whatever, I suppose if it's done in the USA it must be the best way and we're daft not to slavishly follow the same procedures they do.
The way I'd look at it, is that if it's possible in one country, it's possible in another.
But then to date, to the best of my knowledge, we've not suffered the pain of a mid-air between a light single and an airliner whilst both were operating inside controlled airspace in the vicinity of an airfield.
Ah, San Diego perhaps? That was a total balls up, lessons were learned, and procedures changed. It's not the same system anymore, things have changed.
San Diego now has class E "tunnels" through the Class B, no clearance required as it's Class E. Works well. LAX has a special flight rules "tunnel" thorough the class B. No clearance required as it's SFRA. Works well. PHX has VFR transition corridors through the class B, clearance required, I've never been refused, works well.
There have been a few near misses recently in UK "positive" controlled airspace. Only a matter of time before something collides, and the UK will be unable to continue with it's justly proud claim. The problem in the UK is that ATC is totally under-resourced and so cannot handle small aircraft doing something as simple as transiting a class D control zone. By the sounds of it, the systems regularly cannot handle the jet traffic it is supposed to.
In the US, GA is considered an asset and to have equal rights to use the National Airspace. Resources are therefore allocated and available to allow small transponder equipped planes to be safely separated from jets in far busier airspace than you find in the UK. Maybe that is the best way? cheers