I suspect that if you had taken your test in a larger city, then maybe you wouldn't have passed so easily. That is a major problem with the current system, it is almost impossible to get a consistent standard given the geography of our country.
It is up to the motorist, cyclist, pedestrian, whoever to keep themselves appraised of changes to regulations, infrastructure etc. Personally, given the generally low standard of driving, I would support testing every year, because driving is the most dangerous thing most people do and in many professions, ongoing demonstration of capability is now accepted practice.
I have driven everything from a rally car, to a 44 tonne articulated LGV, but I won't get into a willy waving test because variety of vehicles driven is not a measure of drivng competence.
I agree with your last point. The driving test, like any other forms of examination simply measures performance at the time. A longer test with more varied conditions would be better, backed up by periodic re-testing.
3rd party insurance for cyclists can be had for a little over £1 per week.
If insurance and registration were compulsory ANPR would catch anyone withput insurance.
https://www.money.co.uk/bicycle-insurance.htm?track=843976&creative=263313981787&network=s&placement=&adpos=1t2&gclid=Cj0KCQjwquTbBRCSARIsADzW88zgSvdjCSlWn3aTuyvRXjD3tAvKZWEFf2tT-ZNzPnbuuMb4MULA8L0aAqu-EALw_wcB