hmmm. I'm a regular emacs user w/ Doom configuration on top of emacs. I love emacs and I use it exclusively, however it does crash sometimes for me. It's enough to notice, but not enough for me to care.
If you can repeat a crash, please do report it.
If you allow networking, you can do emails like gnus.
If you allow pictures and HTML parsing, you can do a web browser like eww.
I guess you don't have to add too much to get a new domain.
The beauty of emacs is how easy it is to modify it. Lisp is the easiest syntax to learn, emacs hides nothing from the user, and the user can override or add whatever they wish. It really is a proper example of free and open software. To add to this, it's all very well documented, and everything you need to develop (for) emacs is in emacs itself.