One of the (legitimate) complaints about Emacs is that it doesn’t do very well with excessively long lines. Happily, this isn’t a problem for me. I write my blog posts with visual line mode enabled and fill disabled so Emacs sees each paragraph as a single line. Despite that, I never run into problems so it’s not a issue for many (or perhaps even most) users.
Still, if it does effect you, it can be a real annoyance: Emacs can take a considerable amount of time to render the text. Happily, help is on the way. A fix for the long lines problem has been added to the 27.1 Master branch. Some early 27.1 adopters are reporting excellent results with the fix.
If you follow the link at the top of reddit link above, you will see the documentation for the changes. It’s worth reading that to get a feel for how the changes will affect working with long lines.
This change should—but probably won’t—put to rest the notion that Emacs is an old, moribund editor still alive only because a few gray beards refuse to let go. It shows that development is strong and on-going and even long standing issues are being worked on and resolved.