True, but that DRM is relatively easy to handle, and is sort-of a standard (OK, I know Adobe handles it, but it's not a complete walled garden like Kindle). I can borrow an ebook from my library using my browser, download the DRM'ed file, fulfil it (using Adobe Digital Editions), copy to my ereader. I can buy books from Google and do the same. It's relatively straight forward to strip the DRM if you want to. Because it is reliant on a third-party service (Adobe) that has other clients/interests, it's not as likely to change as quickly or as onerously as Kindle's DRM.
Yes, most books you buy from Kobo do have DRM, but a Kobo handles DRM-free files you may acquire elsewhere (e.g. an author or publisher's site) better than Kindles do. Kobos support epub natively, while Kindle requires some sort of conversion that doesn't always work great.
This, my first eink reader was a Meebook M6, Boox didn't release their 6" model yet. My main selection criteria was "it runs android".
It was a really good reader, Kobo, Kindle and co can just be ewaste as they're designed to be.
Kobo fully supports pointing your library at a Calibre server instance to pull books from. You can also access a bash shell by changing a setting. They're very open devices and IMO quite nice.
This is why I have a Boox Android eInk tablet, although I only use it with burner accounts. They run Ancient versions of Android.