An interesting thread. One thing that is an, almost, certainty is that it won't be getting easier or cheaper to get a licence in the future.
That said, turn the riding without L plates on its head. What's the worst that can happen? Maybe being nicked for no L plates, riding without a licence, riding without insurance, having an accident and having a civil law suit against you for several million quid, finding out at some point later in life that you need to disclose all convictions and those stop you working where you need to, going to prison etc.
Simpler to pass a test I would suggest for most people.
People may not like the laws and some of us still remember the days when we brought a 250, stuck some L plates on it and paid a couple of quid for an insurance certificate that allowed us to ride "up to" any cc bike which we brought over the counter at the bike shop (Norwich Union insurance pads).
I brought my first bike,collected it and rode away with no bike experience. The first few miles were errrr interesting.