I just ran across a post from the estimable Howard Abrams on using Emacs as a window manager. There are two dates on the post, 2015-01-12 and 2023-01-11, so I’m not sure of its birthdate but either way the post seems applicable today.
Abrams starts by noting that when he takes on a new job the first thing that happens is that they give him a work lap top. Naturally, he doesn’t want to add his personal data and configuration to his work machine. At the same time, he often needs to make personal notes and perform other non-work-related tasks during the day. The easiest answer is to carry two machines but who wants that? His solution is to install a virtual machine on his work laptop for his personal use.
He wanted a simple environment that mostly runs Emacs so he installed a server version of Ubuntu. He still wanted a graphical interface so he also installed xinit. The surprise is that the only thing he put in his .xinitrc file was
exec emacs
That effectively makes Emacs his window manager. He added a simple directive to his init.el to make Emacs open full screen so it was almost like booting into Emacs. Of course, he discovered he needed a few other applications but those turned out to be simple to add. Take a look at his post for the details.