Something like that, Emacs is my windows manager and start at boot with autologin (I use LUKS crypto root so I do not need to type a password on personal systems). So yes, while I'm using GNU/Linux (NixOS) I can say to a certain extent that I boot directly into Emacs.
And it's not a new thing BTW, many years ago (early 2000s) there where already an Emacs WM (http://www.nongnu.org/xwem) and someone already use Emacs even as a login shell instead of bash/zsh (http://www.sxemacs.org)
You can consider Emacs as a text-centric user environment so the "editor" part is of course there :-)
Try looking on YT about "Notmuch: What email should be", "Introduction to org-ref", "literate DevOps", "Emacs reproducible research", "Conquering Your Finances with Emacs and Ledger" etc they are about few use of Emacs and often they are presented in Emacs itself, sometimes as a WM with the modern EXWM :-)
Also GuixSD (guix emacs package) and Arch (arch-packer) have system management tools inside Emacs, other generic tools exits like proced (top/htop inside Emacs), enwc (NetworkManager wrapper), ivy-pass (pass password manager wrapper), screenshot tool, ffmpeg wrappers for screencasts...
Many services have Emacs UIs like Slack (slack and ox-slack emacs packege), ERC (IRC&other chat client discord included), Jira (-mode), Maxima (imaxima), ESS for R development, various on-line wrappers including hackernews, various Google service wrappers, ix pastebin services etc
Try to look for "emacs $something" and you normally get some results, if you develop try to look for "emacs $language" and you'll find many options (also look on YT&c for thing like web-mode, emmet-mode, ...).
In the end I think Emacs is the modern and last living LispM implementation :-)
And it's not a new thing BTW, many years ago (early 2000s) there where already an Emacs WM (http://www.nongnu.org/xwem) and someone already use Emacs even as a login shell instead of bash/zsh (http://www.sxemacs.org)
You can consider Emacs as a text-centric user environment so the "editor" part is of course there :-)
Try looking on YT about "Notmuch: What email should be", "Introduction to org-ref", "literate DevOps", "Emacs reproducible research", "Conquering Your Finances with Emacs and Ledger" etc they are about few use of Emacs and often they are presented in Emacs itself, sometimes as a WM with the modern EXWM :-)
Also GuixSD (guix emacs package) and Arch (arch-packer) have system management tools inside Emacs, other generic tools exits like proced (top/htop inside Emacs), enwc (NetworkManager wrapper), ivy-pass (pass password manager wrapper), screenshot tool, ffmpeg wrappers for screencasts...
Many services have Emacs UIs like Slack (slack and ox-slack emacs packege), ERC (IRC&other chat client discord included), Jira (-mode), Maxima (imaxima), ESS for R development, various on-line wrappers including hackernews, various Google service wrappers, ix pastebin services etc
Try to look for "emacs $something" and you normally get some results, if you develop try to look for "emacs $language" and you'll find many options (also look on YT&c for thing like web-mode, emmet-mode, ...).
In the end I think Emacs is the modern and last living LispM implementation :-)