It's good to be cautious, but we should not forget that things can change.
As a kid, I didn't like China because I was impressionable and the media told me that China is my enemy because I am Taiwanese. As I got older, I started to form my own opinions. After getting to know China better, I basically became a Chinese ultranationalist. I know many, many Taiwanese people around my age who used to dislike China but now admire it. I am not saying that this will happen to the China-Russia relationship, but I believe it may happen. This is purely anecdotal, but my cousin is married to a Russian man and our families get along really well. I don't think that it's impossible for China and Russia to become friends because Russian people are European and Chinese people are East Asian.
I have some mainland Chinese friends whose parents dislike Russia because they grew up fearing the USSR. However, most young people like Russia these days. There are many Eastern European people, including Russians, on apps like Douyin and Xiaohongshu where they can see that China is pretty cool place. There is an increasing number of Chinese-Russian people in China, especially in the north and in big cities like Shanghai.
Russia is a superpower, so I agree that Chinese people should be aware that if Russia becomes hostile to China, that would be disastrous. Nonetheless, I am hopeful that China and Russia can become real friends.