As the simplest chat tool, WeChat is recognized by everyone.
More and more elderly people have given up QQ and used WeChat purely. Because WeChat doesn't have too many advertisements and pushes, it avoids a lot of troubles, and QQ has many advertisements to push, so I don't like QQ very much in my later years.
Many online games launched by QQ are loved by many young people. They play and talk, communicate and command, and make friends while playing. It is these young people's psychology that makes QQ a favorite of young people.