One of the problems with the Web 2.0 monolith pattern (server + web client) is that it makes community-hosting of services seem much more resource-intensive than it needs to be.
How much of the server resources used by a standard Matrix homeserver install, for example, is used by the Element web client? How much cheaper would it be to run a headless Matrix server, and use native Matrix apps on whatever devices you use?
EDIT: Or a headless AP server + native apps?