1, I'm busy with my own business and don't want to be disturbed in the middle, because sometimes it's not just a question of replying to a message. Once I reply to the other party, I will continue to start chatting, so my rhythm will be disrupted. But I will reply after this.
2. I just saw it and didn't have time to reply. After a while, I forgot about it.
3. I don't want to reply. Sometimes when I see that news is sent by people I don't like, or that there is no nutritional content, I subconsciously don't want to reply, because I don't think it is necessary to reply.