How to increase the number of characters in text messages? Why can I receive a text message of more than 200 words in one go, but have to forward it three times to others?

This is how text messages are sent

The first 70 characters are one text message, and if it is longer, three bytes are needed to associate two text messages. In other words, all 70 words of the first article can be used to post the content. If it is 71 words, then 67 words are the first one, three connecting characters, and the remaining four words use the place of the other one.

In this way, the average length of each long text message is 67 characters