No use cases for this so far.

Mobile service quality is defined by the baseband, which is an immutable blob to the OS. I phone rarely and currently use my old LineageOS phone for it.

I’ve got a support case for my Pixel 7a open due to potential battery issue. If I return it I will buy a different, bigger (6.7") Pixel model. My new Pixel tablet is doing fine so far.

I use tablets to read things when lying down, so notebooks don’t fit.

Matrix (Element), Signal, Telegram. Other stuff probably requires Google services which I don’t use on the tablet. Phone has Google services, but I don’t really use it for messaging other than Signal.

I’m on GrapheneOS on tablet/phone for time being, but I’m fine going back to a dumphone and a Linux or BSD tablet or convertible.