I agree with your sentiment that the Kobo is better than the Kindle from an... ethical standpoint, if you have the money for one. However, it is worth noting that Kindles will always be cheaper than Kobo devices [0] due to economies of scale and lockscreen advertisements (removable with jailbreaking). From a pure cost perspective, and assuming the user is technically-minded enough to accomplish the jailbreak, the Kindle is likely always [1] a better deal.

[0] as of today, 12/8/25, the "base model" Kindle 11th Generation is priced at $109.99 USD, and the respective Kobo Clara BW is $139.99 USD.

[1] I say "likely always" to cover my bases. To my knowledge Calibre supports Kindle, just not as well as Kobo. That said I have found that the KOreader app is more than powerful enough for my use case (reading my own epubs, using dictionaries, etc.)