The same as most people have home WiFi routers running 24/7, we should
instead have small, cheap and low-powered computers running GNU. Those kind
of computers should be capable of functioning as a WiFi router (and much
better!) and also have servers for email, web, XMPP, federated social
networking and anything you want to install.
We seem to have the hardware needed for this (single board computers), but
not the software. We need an OS that makes this easy to manage.
We have YunoHost: https://yunohost.org
And the FreedomBox (with very high ambitions in term of resilience and
privacy) is slowly but surely reaching a usable state:
https://freedomboxfoundation.org
Both projects are based on Debian. Be careful not to activate the "contrib"
or the "non-free" sections of its repository if you value your freedoms.