Is goldfish easy to raise or koi fish easy to raise?

I once raised koi fish for nearly a year. Why did I raise koi fish? I saw beautiful pictures of koi fish on TV, and impulsively gave goldfish to people one by one, and began to raise koi fish. So I went to an aquarium store to buy koi fish. By raising koi fish, I got first-hand information. I feel that koi fish is much better than goldfish, and there are fewer pests and diseases. Koi fish has a strong body, but he just bought a lot of koi fish, a local cannon. The color is too ugly. And koi fish's body is monotonous, and it's boring to raise. So I went to the aquarium store and traded dozens of koi fish for some goldfish, and started to raise goldfish again. There are two reasons for abandoning koi fish. The main reason is that the place at home is too small to hold a vat of more than one meter. Secondly, the price of koi fish is too expensive. After careful consideration, I won't keep koi fish for the time being. When I retire, I will find a way to support koi fish. In addition to goldfish, goldfish are difficult to raise, and there are many pests and diseases. Moreover, goldfish are delicate, and it is inevitable that they will die if they are not carefully raised. I have kept goldfish for nearly 30 years, and there are countless dead goldfish. I am a veteran goldfish player, ace goldfish killer ...?