[Uvix]

Most readers only buy books from their device’s store, so they don’t need to worry about sideloading. And then once they’ve done so, they are hesitant to switch because it’s hard or impossible to extract yourself from Amazon or B&N or Apple’s ecosystem without losing content.

Ideally everybody would only buy DRM-free ePubs and audiobooks but realistically people don’t care. And I don’t see a repeat of Apple forcing DRM-free music happening here.

[ethanbond]

FWIW, in case it's useful to other readers: removing the DRM from a Kindle ebook is super easy using Calibre and the DeDRM plugin. You put in your Kindle's serial number into the plugin, download the ebook from Amazon, drag-n-drop into Calibre. From there you can convert it to pdf for specific formats, e.g. I use the Supernote A5X which is a great reading and annotation experience.

[bentley]

I would rather spend my money on books from publishers who provide DRM‐free epubs, like Tor Books or No Starch Press.

[oakhaven]

I think there's a lot of sideloading. Buying non-{english,mandarin,spanish} books happens often in other book eshops, usually language- or -country specific. If you supply your kindle ID, they are able to send it straight to the reader, but the book collection is then stored in the local eshop (or more eshops if you buy from multiple). That's why Calibre exists.

[jwells89]

At least the Books app on Apple iOS/macOS will manage and read plain old epubs and PDFs without issue, even if you’ve already bought DRM’d books from Apple’s store.

It’s really only big name e-ink readers other than Kobo that have this issue.

[Uvix]

It's not "other than Kobo", though; it's Kindle specifically (and only with ePub, it takes PDFs). The other devices will happily take both PDF and ePub.

As for Kindle... for most users Send to Kindle is going to be more convenient than sideloading anyways, and that does take ePubs now, so it's not a huge usability hit.