[haritha-j]

Interesting. I generally hate proprietary software, but I've actually been really satisfied with the kindle UI. I don't use the store at all, simply email epubs to it directly. (I usually only move 1-5 books max at a given time, so this process feels really simple to me). The only adjustments I need are the text size and front light, battery life is amazing. I'm guessing this would be really useful if I had advanced needs, but for just reading epubs, kindle is a really good UI.

[loloquwowndueo]

You must have a newer kindle. Koreader was basically my best bet once mine (2012 vintage) stopped being supported by Amazon. Native epub support plus other goodies. I’m sure you’re aware that emailing an epub to your kindle converts it to mobi before sending, potentially mucking up the formatting.

[haritha-j]

I think mine is from 2019. I didn't realise it wasn't natively displaying an epub. I haven't noticed any breaks, or maybe I attributed any errors simply to the original epub and didn't realise it was a conversion error. But also the things I read are quite plain and text heavy so perhaps that's why.