Sorry, but I completely disagree.
Just for background, I live in one of the most cycling-friendly cities in the UK, with half a dozen bike shops within easy reach of my home. Everyone in my household cycles, with decades of combined experience. We all have some of the most powerful lights you can buy from those shops on our bikes, often in multiples, and none of the flashing LED stuff for primary lighting. Obviously this is significantly more than a lot of people cycle with (or than the law requires for that matter).
You might have thought you had adequate visibility on your dark country roads, but in reality you certainly had blind spots all over the place. On a mostly empty and level road, with a bit of natural lighting from the moon and stars, you'll get away with that up to a point. But on a poorly maintained city street covered in potholes, debris, painted-on road markings, irregular kerbs and so on, you won't.