What evidence do you have apart from pure guess work?
Look at the pass rates - are you seriously telling me that only 40-50% of people are fit to drive at the time they take their test? The wide variation in pass rates (up to 60% in some places, as low as 35% in others) also tells you that something isn't quite right with the system. I actually think it's somewhat of an insult to the majority of driving instructors, as they're simply preparing people to drive the DSA way for a test, rather than for driving in reality.
What conditions? All areas of driving are covered whilst taking driving lessons. Motorway driving lessons are optional.
Since when? There's no requirement for a driver to do anything but drive on single carriageway roads - and certainly no requirement for them to drive at night, in heavy rain, etc. It's perfectly possible for someone to start learning at the beginning of summer, only drive in the sunshine and on single carriageway roads, and never have to experience heavy traffic at 70mph in the rain. How on earth can they be 'fit to drive' if they never have?
I don't see any difference, the UK system is practically the same. Why remove the test? Don't tell me you have failed several times but you think you are a better driver than most people on the roads!!!! By the way the 'exam' is a simple drive with someone assessing you in the car - nothing difficult involved if you are a competent driver.
Who defines competent? I know someone who was failed for 'hesitating too much' - surely it's better she waits until she knows it is safe? I can understand if she wasn't getting up to speed - but the fail came from waiting for a couple of minutes at a stupidly busy roundabout where the only option was to either throw the car forward or wait.
And no, I've never sat the test in the UK - never needed to. But I can drive fairly well, and I'm supposedly at 'test standard' - but I can tell you that I don't think I am. For a start, I'm a poor night driver, and I'm not completely confident at 70mph on the dual carriageway. For those reasons alone, why on earth should I be able to pass a test and drive big powerful cars?
The UK system is just a lottery, really.