Why do you think UK drivers test is better than foreign one?

I would argue it's not about being better or worse than another country, but if 1 in 30 drivers have a different understanding then that's a risk. By doing a driving test in the country you live in you gain a greater understanding of what it's like driving in that country.

As a simple example I drove around Northern France and the first day almost went flying off the motorway slip road as I didn't realise how tight they tend to be in France compared to the UK and Ireland.