The issue such devices have in practice is upfront cost, compatibility, the need for port forwarding, and the lack of redundancy so you don't lose your data. Among other problems but these come to mind. Centralization solves those problems because you can connect to a server instead of port forwarding, your data might be stored across 3 servers, the cloud storage might be as cheap as free, and applications are designed to work seamlessly with a small number of big cloud providers.

In the depths of my soul I would love to re-decentralize the web. I truly believe data centralization will cause people to suffer a lot. decentralized tech needs to solve so many problems before alternatives to centralization become viable. Centralized approaches also improve over time and are a moving target to keep up with.