Unless you know every single Chinese teacher and their individual teaching style to make an informed assessment of their teaching style, it is a generalization. You cannot say "all Chinese teachers" use a specific method when you don't know every Chinese teacher!

PPTs are helpful, but not everybody's cup of tea, and a badly made PPT can be unhelpful and/or boring for the students. If the person making it has only a rudimentary grasp of the grammar point involved, a PPT is either a crutch to help the teacher present the point, or worse, filled with inaccurate information which doesn't help the students. I enjoy making interactive, animated PPTs which my students love, but then I'm rather handy with PowerPoint and I know my grammar! For example, I have one where Chun-Li and Ryu from street fighter battle over definitions of words (adaptable for level), the class (in two teams) guesses the definitions and if correct their character lands a blow on the other, after 3 successful hits the character wins and points are awarded. It really makes vocab games much more real for YL students... Although adults enjoy it just as much when used as a grammar auction tool, rather than definitions! (if anyone would like a copy of this ppt for use in their classes, I am happy to share! Please email me if you are!)

As for the not using audio, this is irresponsible. Audio tasks are paramount for students learning to comprehend native speakers and allows them to both hear different accents and voices to their teacher's and also helps them hone their listening skills (for tasks such as information gathering or listening for specific information). The Cambridge website has links to audio content based on every level of the CEFR for free use and downloadable content for specific exam courses, such as PET, FCE and CAE. It's really beneficial to your students to include and audio component to their class.