書 and 者 don't sound similar in modern Mandarin due to historical phonetic changes. They were more similar
in older Chinese.
Change in form
Due to historical stylistic changes, this component is less similar to 者 than it was in ancient scripts.
Character Evolution
BronzeMid Western Zhou~900 BCBronzeLate Western Zhou~800 BCBronzeSpring and Autumn771-476 BCSealWarring States (Chu)475-221 BCSealShuowen~100 ADClericalQin221-206 BCClericalEastern Han25-220 ADClericalEastern Han25-220 ADRegularModern