Paper chromatography is a method for testing the purity of compounds or identification of substance. It is not that the other methods are not done in the school but it would be formal to say that paper chromatography is more often used than any other chromatography methods for certain reasons.
-Paper chromatography is so cheap that it can be made and tested directly in the lab. Other methods like HPLC are so expensive for it to be executed in the lab.
-Paper Chromatography is easy to set up, to dismantle, to perform and to clean.
-Other methods such as HPLC, gas chromatography (GC) and columns are methods to determine the existence of something in a sample. If paper can already do it, then why venture on other methods.
-The HPLC and GC units are so expensive for every school to have.
But if there is a research to be conducted, it is more efficient if other chromatographic methods should be used other than the paper chromatography.
You have no idea how much you have helped me, thank you so much!