I would not recommend emacs as an editor these days to most developers, but it absolutely still remains one of the most visionary and well thought out pieces of software ever written. It is both hilarious and depressing how emacs has been literally decades in the future over all of its 45 years of existence, without even the most obvious clearly superior aspects diffusing into the sea of idiocy surrounding it at a rate faster than one or two decades per feature.
Not everything about emacs is great, or even were great, without downside (for example the extreme malleability and customizable bring a raft of problems as well). But a couple of things really were and in some cases still are just obviously, massively, better without the rest of the world being in any seeming hurry to adopt them.
Incremental search is the prime example. It has finally become ubiquitous, and yet Emacs was basically the only thing that had it for well over a quarter century. As Raskin quipped in The Humane Interface (2000), search is either incremental or excremental (unfortunately he seemingly also tried to steal the credit -- he had an interesting mode-less variant of incremental search in Copy Cat which deserves notice, but it still postdated emacs by quite a few years, and I've never seen him acknowledging emacs as prior art). So I would really love to understand why neither netscape or basically anything else in the 90ies had incremental search, despite often being written in large parts in emacs by people living and breathing emacs such as JWZ.
And to this day emacs remains one of very few programs with a proper (i.e. non-linear) undo system or a clipboard not suffering from severe dementia, or the ability to actually ask "what happens when I click here?".