@bonifartius Onyx/BOOX does have an account built in for their device, but you dont need it. In fact that make it intentionally so you dont need it (offering local LAN options that circumvent needing an account for much of the functionality).
So if that is your concern then any of the BOOX/onyx products will do nicely, and they have cheaper options (this was this most expensive product).
Also keep in mind color isnt worth the price for most people when you consider e-ink color isnt particularly vibrant. You get noticable but muted colors.
But if you want the colors it is the best you can get on the market in terms of color e-ink, in fact its the only color e-ink that is production ready and in tables (other brands have color e-nk but they use the same tech with muted colors).