Please don't 'buy' digital items from Amazon, because you won't actually own them. Pay extra, support your local bookshop and get a physical copy which you will actually own.
I really appreciate that sentiment, but on the other hand 98% of the books I buy I won’t read a second time (because reading a new book will almost always trump rereading an old one), so I’m actually fine with not owning most of them, especially at $1.99 prices. The few that I deeply care about I buy a physical copy of.
It's a trade-off. I love the convenience of ebooks, but not owning my books is just categorically unacceptable to me. I want my daughter and anyone else coming after me to have free access to them, not to have to jump through Amazon's hoops (if such hoops even exist) for access.
I have a Kobo that I use to read the non-DRM ebooks I'm able to acquire. One such source is downloads from the Kobo store, when publishers make the non-DRM file available.
I use a kindle but I have never bought a book on the kindle store ever (been using it for 10 years). Totally doable and not hard to avoid... especially since the smaller stores not only have better sales but the author typically gets more money too.
They used to allow downloads of all books, which you could then rip the DRM from, but they got rid of that last year. Huge disappointment, and is why I don't buy books on Kindle anymore.
It's an enjoyable read, hopefully it's the start of a whole new arc in the series with more to come. My only real complaint is it's short and I want more. If you never read his other Interdependency series, it's also great.
Alternatively[1], for those of us who have enough clutter: Buying it digitally means you've paid for it. The author gets their cut, and you can now seek out unencumbered formats that best serve your usage with a clear conscience.