Android tablets are probably part of the problem. I still use my Sony Z3 Compact tablet. It is thin, waterproof, supports a SIM and SD card. I have never found a good replacement, though I'd like to. I mostly use it for reading ebooks and Pocket and RSS feeds so it handles the tasks well, but no upgrades, eventually it will need a new battery and now I see root certs are built in guaranteed obsolescence (like on the iPod touch). Unfortunately I can't find any high quality Android tablets as manufacturers have relegated Android tablets to the price sensitive consumer demographic. And iPad mini isn't waterproof.

It also works well with older Bluetooth BLE devices that won't connect with my newer Android phones.