I'm writing this because I think many people are unaware of this feature of Emacs and might gloss over it in your post.

As far as I'm concerned startup time is next to irrelevant in Emacs, since you can start an Emacs server once when you boot up and then just run clients that open and connect instantaneously. That is, you can then run 'emacsclient' from the command line in any terminal you want, and it will open a working Emacs instance in a few milliseconds.

Here's blog post that describes this feature:

https://brainlessdeveloper.com/2017/12/27/making-emacs-work-...

The blog post above actually overstates how difficult it is to start working with Emacs in this way. It's dead easy.