I use a Boox reader, but pretty close to the same experience. For me, I either buy the book from one of the many places that lets you download epub, or buy it on the Kindle store and download it from Libgen. It's really a non-issue. I've only run into one or two books I wasn't able to get an epub of, and those I ended up reading on the Kindle cloud reader on my laptop.

What are your favorite places to buy books that let you download the epub versions also?

Yes completely.

I have both an old Kindle Paperwhite 2nd Gen I think and a Kobo Clara.

The kindle 'lives' in the car and the Kobo at home so I always have something to read.

I use Calibre to sync to both.

Rather than directly accessing Amazon from the Kindle I download bought books to my PC then strip the DRM - so I can read the same book on both the Clara and Kindle.

See: https://github.com/noDRM/DeDRM_tools

I'd say that the initial awkwardness is from deliberately not connecting the Kobo or Kindle to the internet to stop them from 'phoning home' when you set them up. The Kindle is easy - just don't connect it, the Kobo seems to insist but there's a simple step-by-step to bypass the enforced sign up on the Clara I use.

See: https://yingtongli.me/blog/2018/07/30/kobo-rego.html - basically SQL commands.

and you can get firmware updates for the Kobo devices via

https://pgaskin.net/KoboStuff/kobofirmware.html

and they are easy to apply - drag / drop.

I don't get books from Kobo's site as it used to be hard if not impossible to strip the DRM from them - which meant I couldn't read them on my Kindle.

Hope that helps.