Stagnation is a good thing. It means you got it right. Your search has found a local optimum. For example, the screw cutting lathe has been stagnant for about two and a quarter centuries[1]. Sure, there have been incremental advancements--geared heads, power feeds, numeric control--but the basic UX is fundamentally the same. You have gears (virtual or physical) to control the feed rate of the cutting tool, and hand wheels to move the saddle and compound.

EDIT: I'd bet the unix shell experience is similar. It's hit a pretty stable point where it's unlikely to be revolutionized. There are certain improvements--tools like atuin[2] are nice--but fundamentally the UX will remain the same: you type text commands into a prompt, the basic readline controls work, you may have tab-complete. Text editing has hit this same stable point. You're not going to do better than vim or emacs.

EDIT2: Actually, I think GitHub is a good example of this kind of good stagnation. The code review experience of GitHub's competitors is largely the same as GitHub's.

[1]https://ocw.tudelft.nl/wp-content/uploads/ED2011_2_Fabrikage... [2]https://github.com/atuinsh/atuin