I'd argue the Unix command line ecosystem has only 'won' in the sense that many developers are familiar with it. I don't think it is technically the best we could do if we were starting from a blank slate.
Now look at what happens on Windows. Devops can use PowerShell to hack together something quickly, but if they want to do something more complex you have the option to easily add new PowerShell commands and data types because it's all based on .NET so you can pull in any .NET code you want, whether that's something you write yourself or from an existing library.
You could do the same with Bash, but people don't do as often, I would suggest this is because it would tend to rely on plain text and regular expressions, and programmers tend to prefer using better specified data types.
The lowest hanging fruit gets picked. "Lets dump absolutely everything and NIH the whole thing for a single time 5% performance increase" doesn't sell well when that one time gain is expressed in the amount of time it takes hardware or network capacity to improve 5%, or fixing poorly scaling algos. Also insert the usual analogy of the ratio of the cost of microscopically faster hardware vs the labor cost of extremely expensive rockstar ninja programmers.
Also its assumed that change will lead to improvement because anecdote, or because change is always good. However, "the thing that won uses text, so naturally we gotta get rid of text" doesn't sound like a wise plan.