I'm not terribly worried that Kobo will go out of business overnight, leaving me with purchases no longer accessible. I have a big three list where I'm willing to trust to the seller to keep my books on hand: Kobo, Amazon, Audible. The worst bad case scenario, extremely unlikely especially without a long lead time with warning signals, is that there'd be one of those: "Download your books by X date before we go offline" notices.
As I said, more trouble than it's worth to me right now.
I'm not claiming that the odd book can't go astray because of rights. Oh, well. I'm sure I'll be able to bear up.