Google cooperating with the Chinese government's censorship and data collection would be a concern, but the last five search fields you used were almost certainly censored too. Search engine design is not just about tech, it is also about ethics and most designers don't think like librarians. https://theintercept.com/2018/08/01/google-china-search-engine-censorship/
When I want to buy a paper book, I search bookfinder. Is there a similar tool to see if anyone sells an ebook without DRM of a particular title?
When I do not know the store, I have no way to know whether they just will mail me an ePub, or want me to log in to some baulky, script-heavy cloud service to download the code to let some non-free software download the actual book. I find that the second kind of shop is not worth the trouble.