Why not show off your wealth?
Imagine that your relative is in big trouble and needs one million yuan for emergency, but he knows that you are wealthy and have tens of millions of yuan. At this time, he may directly "morally request" you, or even use more extreme methods, because he thinks this is the fastest solution. You gave him 800,000 yuan out of kindness, but he may not take it too seriously. After all, it is just a small amount for you and it is not stressful, so he may not be so grateful.
Besides, even if you gave him 3 million yuan, it would be just a drop in the bucket for him, and he would not be able to completely get out of the predicament. On the contrary, he may still mutter in his heart: "He is so rich, giving me so little, it's not good enough! If I have so much, I will definitely give him more without hesitation." But he will comfort himself and say that not everyone is as grateful as he is.
On the other hand, if he doesn't know that you are so rich, and you lend him 300,000 yuan, he may be very moved and regard you as a savior. If you work a little harder and get 600,000 yuan for him, he may think you are his second parent and be willing to do anything for you in the future.