To be clear, you program using ed and the command line instead of ever using an IDE? The said programming environment, you said 'line editors are nice'.
This is the same nonsense game people play where someone says "that's like taking a ship to cross the ocean instead of a plane" and someone else says "I like taking ships, I want to get fresh air for three weeks of solitude instead arriving the next morning"
I do for every language that isn't Common Lisp! I learned to program on a machine that had a copy of vi that refused to go into visual mode; instead of trying to fight it, I started using ed.
Everything about UNIX is oriented toward being a programming environment in itself. There are plenty of developers who just use UNIX as their IDE. Drew DeVault, as an example, is pretty notorious for it.
Complexity distracts and makes efficiency impossible. Modern IDEs are nothing but complexity. UNIX-as-IDE simplifies.
UNIX has all of the tools, and unlike IDEs, it allows you to seamlessly add them on. UNIX is more "cybernetic enhancement" to the IDE's "prosthetic limb."
ed is actually really useful if you're wanting to rapidly iterate on a program. There's a reason Ken Thompson advocated for it up to his retirement (which was very recently, mind).
