lcalamar if all you want to do on your Laptop-Tablet is checking mails and messengers, I'd advice to stick to e-ink as well. Much better for the eyes and much more battery life at the cost of refresh rate (which you don't need for reading).
On the other hand, GOS on the Pixel Tablet is unbeatable when it comes to security, control and privacy in my opinion if that is your utmost priority. And you get to watch movies and do all the things e-ink is not good for.
Last but not least if you want to navigate by mouse a lot, I find the gestures are harder to manage and in general it's a bit janky on any android tablet (set up old school button navigation to make it a bit better). But in this case a regular laptop using Linux Mint or Fedora would probably fit the needs best, and you can choose from a huge selection of vendors, screen sizes etc. at the cost of security and usually no e-ink.
As so often you'll need to ask yourself what you really want and need. From the few things you shared, I'd say go with an e-ink android based reader since most you do is reading text.