That would be great for upsets and our entertainment, but might be bad business. The more and larger round robins there are (in qualifying and group stages), the more likely the big teams will be through to the final rounds, as a big team can usually be depended upon to recover from one early loss if the loss doesn't knock them out of competition. Early upsets of teams like Germany, Italy, etc., could drive down revenue from televised games as fewer people from those markets—and fewer neutral fans who want to see "the talent" and aren't very concerned with Cinderella stories—tune in.

From UEFA's angle, I imagine they feel good about the system they have. They have four knockout rounds to draw the big crowds, but these are usually seeded in such a way that a few major teams can be expected to make deep runs. Meanwhile, every participating team is guaranteed three matches as a warm-up to the big event.

This year's bracket, with many of the best teams all on one side, is an anomaly. You can't keep out anomalies, though. On the whole, the system works as they like it to.

I'd like a big knockout tournament, but it doesn't seem feasible and in any case might be too fatiguing in the space of a month or so. Gradual build-ups are good.