> that's how apps decline in popularity and eventually die, thus decreasing the value of the huge amount of time you've invested

That's true. That happened to many apps that I invited into my workflows over the years, and I have tried multitude of different things.

Emacs has been the complete opposite in my experience - the more I use it, the more value I am able to extract over time. Because Emacs is not "an app", it's a full-fledged system that offers endless customization and extensibility. The longer you engage with Emacs, the more you discover its potential to adapt, integrate, and evolve with your work habits. This makes learning Emacs an investment that continuously pays off, as you unlock new capabilities and refine your workflow.

Pretty much any other app that I use every single day can be replaced with an alternative or even completely removed from my toolbelt and I may not even feel the impact in the long run. There's no alternative to Emacs. Nothing comes even close to what I can do with it today. I'm 100% sure, even ten years from now that will remain the case. Unless there's a "better fork" of Emacs that comes out, built on the same/similar principles.