Are rainbow fish endangered?

A few months ago, I bought some rainbow fish at a fish shop near my house, and yesterday, a friend of mine came to visit. When my friend visited, he looked around the house, and his attention was focused on the large aquarium containing the rainbow fish. My friend said that this type of fish is difficult to find and obtain because no one breeds it, and it is endangered. Is his statement about rainbow fish being endangered true? So, what makes it endangered?

My friend also asked, "Is keeping rainbow fish difficult?" I just answered, "It's not that difficult, although sometimes it's difficult, hehe." Do you think it's difficult to keep rainbow fish?

Thanks ❤︎