This is probably a huge factor for sure. Both the UK theory and practical tests are somewhat tricky, at least compared to those in places like the US. Many people will fail them the first time around, and a fair few will fail them multiple times.

The official statistics have a rate of about 40-60% for these tests:

https://www.gov.uk/government/statistical-data-sets/driving-...

Though it definitely varies by area:

https://www.gocompare.com/motoring/reports-statistics/drivin...

It's closer to a school exam in terms of difficulty, rather than the quick drive around a parking lot that it seems a lot of places have.

So people seem a lot more prepared than in many other places, since they actually have to be able to spot hazards and do driving maneuvers to get their license in the first place.