Up here in Canadaland, Kindle is useless for library books, also, they're limited in the files they can open.
I have a Kobo because I can load PDFs, and I use mine to read pirated textbooks and articles.
I radically prefer reading with e-ink over reading on my phone or tablet, so it's worth the premium to me to own the device. Also the battery life is amazing, so it's ideal for travel because I basically don't have to worry about charging it.
It is a luxury, unnecessary device, so you should absolutely question the added value it would bring to your life and how often that value would really play out.
I actually have 2 Kobos, a small one that I read to fall asleep and a large one that I use to read textbooks and academic papers. Each has definitely provided more value than they cost. However, now that I've switched to listening to textbooks, the large Kobo isn't very useful for me. That said, DH has started reading a ton of long academic articles for work, so he's going to try the large Kobo this week. If it doesn't add substantial value for him, then I'll sell it.