I guess my point about DRM is more that the books I want to read are generally only available in DRMed formats. But maybe that's not true? I don't use an Amazon e-reader, for what it's worth.
There's a calibre plugin that removes DRM from most epubs and some Kindle books. It's a pain to set up, because you need old versions of Adobe Digital Editions and/or Kindle, and those run on Windows (I haven't tried them on Wine). But once it's set up, it works fine.
If you live in the US then you might check your local, public library. They've often got volumes of e-books (pun intended :) ), and you can borrow them for a while. Still DRM'd but an easy and free way to access books
It's going to largely depend on the publisher. The publisher, not the platform, controls whether the book is sold with DRM or not. The majority are, yes, although the one genre where that's generally not true is Sci-Fi. There was a time, at least, when most of the major sci-fi publishers opted not to sell their books with DRM, because they thought it was an abuse of technology. Not sure how much that still holds true, but publishers like Tor still sell all of their stuff DRM-free.