"Shouldn't" refers to the functionality of Chinese characters. Practice has proven that Chinese characters themselves are advanced characters. For example, in terms of computer entry, it was previously thought that only Western characters could be entered through computers, and Chinese characters could no longer adapt. The needs of the computer age are backward writing and should be abolished. However, since the Chinese invented the five-stroke font, various Chinese character input methods have emerged, and now there has been a situation of tens of thousands of "codes". Chinese character input is even faster and more convenient than Western input. Now it has been proven that Chinese characters have advantages over Western languages ??such as being less likely to be forgotten and containing greater information. It is precisely because of these advantages that Chinese characters are advanced writing. Why should advanced things be abolished?
"Impossible" refers to the historical aspect of Chinese characters. Chinese characters are in the same line with Chinese culture. The classics and history are recorded in Chinese characters. Chinese characters have been abolished. It is difficult to imagine that Chinese people read ancient books as if they were reading foreign languages. What would the same translation look like? What cultural heritage is there to speak of? It can be said that Chinese characters have been deeply imprinted in the genes of the Chinese people. Without a unified writing system like Chinese characters, perhaps China would not have become the only country among the four ancient civilizations that has not been fragmented and remained unified after thousands of years. Chinese characters have also made calligraphy and seal cutting a part of Chinese culture.
Of course, Chinese characters also have some shortcomings. Therefore, some people have proposed to abolish Chinese characters, but in the end they have not done anything. Only the Chinese Pinyin program has made up for these shortcomings of Chinese characters. This just shows the power of cultural inheritance! It cannot be easily abolished. It also proves the phrase "should not and is impossible" from the opposite side.
The above is my understanding of this sentence. If this sentence comes from an article, perhaps the sentence "should not and cannot be" has been explained and answered in the context, so it is best to explain this sentence in conjunction with the full text.