Since these E-Ink phones all suck in specific ways or have uncertain compatibility with US cell carriers I carry 2 devices, my Android smartphone (which I've dumbed down in a similar way to you) and a Boox Palma 2 (which I use for reading articles and books).

I pretty much use my Android in grayscale only for texting/2FA, phone calls, and occasionally email. I entirely disabled the web browser. If a restaurant has QR code menus I don't care anymore, I'll just leave. If I'm "bored" I'll pull out my Palma and get some reading in.

That's a nice combo. Disabling the web browser is a good idea, thanks :)