I f–king DETEST DRM! I think of it as extortion… it’s morally equivalent to extortion anyway…
What I nearly always do when I can - (requires a Windows “workflow”) is remove the DRM and save a DRM free version of the e-book (I mostly use epub). If that doesn’t work?
I bought the thing, already - so - I locate a DRM free version of the same ebook via “alternative means” (e.g. bookzz.org, or a torrent) - so I might have the DRM version of the book on my Kobo, but I keep a “backup” DRM free version stored in my e-book repository “off site”.
Recently happened when I bought Neal Stephenson’s latest book “Fall: Or Dodge In Hell” (“sort of” sequel to “reamde”) via Rakuten / Kobo … my work recently started blocking Adobe Digitial Editions, so I couldn’t remove the DRM… so I went to bookzz.org and grabbed a DRM free epub file…
DRM is evil… like region locking of digital content… what happened to the free market? Isn’t this bulls-hit against the principle of “world trade”?
Any Linux users on here had any success getting Calibre DRM removal plugin to work? I use Calibre - but I’ve never gotten the DRM removal to work… Just last weekend I decided to plonk my Calibre “database” on Dropbox - so I look at the same book collection from my home desktop, my home laptop, and my work laptop…
Here’s a more recent “thing” that happend to me.
Rakuten / Kobo only had book 1 of the Foreworld Saga / Mongoliad to purchase… I found outher sources for books 2 and 3… NOBODY had books 4 and 5 except Amazon (and I detest Jeff Bezos - he’s the “evil” that google are talking about with their “don’t be evil” motto) - so I sold my soul and bought e-books 4 and 5 for Kindle… how can I read them on my Kobo? I can’t!!! I don’t have a Kindle… I can run Kindle’s app on Windows or my iPad… no solution for Linux or Kobo… Installed the Kindle app on my work’s Windows 10 laptop (using VPN and resktop!) - installed a couple of Windows only apps that promised to remove the DRM (can’t remember which one worked - could have been “Any eBook converter” - could have been “ePubor Ultimate”) just so I can read them on my device… PITA
This is anti-competitive extortion!
As for Steam? I do realise the implications, but at least Valve offer multi-platform solutions… It was Apple who stopped their game streaming client app for iOS, not Valve… 
And in thirty years I’ll be 87, and the men in my family tree hardly ever become septengarians, never mind octegenarians 