A device I'd really like to have would be something like a phone but would replace the need for having any cloud services. Imagine if it had a really large drive where you could just keep all your media, and if it had an API that's something along the lines of NextCloud where it could expose calendar, contacts, email, music streaming, photo gallery, video streaming, etc. that your other devices could connect to.
Since you carry your phone around everywhere anyways, there would no longer be any need to have cloud services because their whole raison d'etre is to act as a central server that allows you to sync data across different devices. If you just carry the server on you, that problem goes away entirely.
You could also have a dock with a backup drive where it would just automatically sync when you plug it in at the end of the day. This way if the drive died on it, you'd always have a backup ready that you could swap in.
Another neat thing you could do would be to have a dock in a shape of a laptop with a big screen, keyboard, maybe faster CPU, more RAM, a good video card. This way you wouldn't need a separate laptop, you could just plug your phone in the dock and voila.
This approach would result in way better privacy because all your data would always be on you as opposed to some server somewhere. It would also be way more reliable since you wouldn't have to worry about network connectivity. You'd still need some external services like a mail server, but these would just be endpoints you use for communication.
