I believe the solution for all this Amazon Kindle shenanigan is not about buying a Kobo. It’s about how we do not allow corporations to determine how we protest. Responsible consumption combined with political and social activism is a more sustainable way to challenge corporate power.
There are diy options like the OpenBook from open source designs and there is the PineNote that last time I checked wasn’t really usable to daily drive.
Those options are more expensive, more cumbersome and you can’t get them second-hand, but they are an option.