I have an unappetizing question about sushi in Japan, and I apologize in advance for possibly being disrespectful towards the Japanese culture.

There are amazing sushi places at the Tsukiji fish market in Tokyo, featuring "absolutely the freshest fish you can get". Indeed, years ago, I woke up early in Tokyo one day, went to the market and enjoyed a great sushi breakfast (without any ill effects afterwards).

In the EU, all fish used for sushi must be deep frozen per official regulations, in order to kill off any worms etc. living in the fish. I understand frozen fish is widely used for making sushi in Japan too.

So what kind of fish is actually used at the popular sushi places at the Tsukiji market? Is it basically the same frozen fish every other place is using? Then what's the point of eating it at Tsukiji, paying almost 2x the usual price? Or is it indeed fresh fish, and you have a risk of being infected with worms after eating sushi there?