My method has always been to buy physical books (which is also better to support the author, because they get a bigger % of the price you pay.
And then, there are other creative ways to download the ebook... (without buying from Amazon, or other monopolists.)
https://www.reddit.com/r/Calibre/comments/1q1uza4/successful...
If publishers/authors want my money, they can release a version without DRM.
Calibre web and calibre web automated downloader remove a fair bit of the clunk.