Before I purchase a book, I always download an .epub file from Library Genesis, and convert it to .mobi using Calibre. Then send it over to the Kindle using em

Before I purchase a book, I always download an .epub file from Library Genesis, and convert it to .mobi using Calibre. Then send it over to the Kindle using email. If I like a book after 50-60 pages, I purchase an .epub file and then convert it through Calibre and load it. Kindle is the worst device imaginable for reading research papers or technical books. It's black and white, for god's sake! And small. I have a separate tablet for reading papers, especially skimming new ones from arXiv. When, reading in detail, I do it through Okkular in my Linux desktop.