Upgrading from Kindle Oasis 10th Gen

I'm considering the following three ereaders in no particular order:

Kobo Libre Color
Pocketbook Era
Pocketbook Inkpad 4

I don't need color but I didn't want to exclude the Kobo. I don't think the Kobo Libra 2 is produced anymore.

Technically, which is the better reader?

I need:

USB-C
Waterproof

I would like:

Flush screen (no dirt in edges)
Fast response/refresh time
Privacy focused / no Ads or collection of private data / Less store integration
KO Reader