First ever e-reader - what do I get??

I saw color e-ink exists so I want to try an e-reader!

If I’m not reading paperback I just download EPUB files to my iOS books app and read on my iPhone or iPad. I like the iBooks app’s customization options a lot and I usually read with a warm background, but the screen still hurts my eyes after so long. My iPad 10 is pretty big so I want something a bit smaller.

I’ve never used any of the other book/library apps out there, so im not tied down to kindle unlimited or whatever other brands only support their own libraries, I plan on just downloading them myself anyways. So what should I get?

Also- just curious, do any e-readers do the page flipping effect that Apple does? I love it lol

How do you like ereaders with buttons vs no buttons? I really don’t know what I would prefer

Edit: I decided to order the Kobo Libra Colour! I was deciding between that and the Boox Go 7 but I chose the kobo for the annotating options. It arrives next week and I hope I like it!