Is it impolite not to reply to other people's messages?

If you don't reply to the news for a long time, it is undoubtedly impolite. Personally, I have come into contact with many people who don't return messages, both familiar and unfamiliar. The most disgusting person is that he doesn't reply after I send a message, and then that person sends friends as usual. After a while, he casually asked me to help him buy things. I hacked him afterwards, and I didn't know him very well anyway.