A desktop environment is a waste of resources on a system where you’ll only use it to install and occasionally upgrade a few server applications. The RAM, CPU power, and electricity used to run the desktop environment could be instead powering another couple of small applications.

Selfhosting is already inefficient with computing resources just like everyone building their own separate infrastructure in a city is less efficient. Problem is infrastructure is shared ownership whereas most online services are not owned by the users so selfhosting makes sense, but requires extra efficiencies.