I recently used it in a legacy site. I had forgotten most of it but I remembered enough. Turns out knockout introduced components, around 2015 or so.

Yeah, actual components like you’d encounter with any modern framework/library like React.

It has some nuances but they are pretty much real components, and I was able to make some pretty advanced functionality in an otherwise typical spaghetti code disaster.

Even wrote unit tests for it. People were in disbelief any of this was even possible.

Turns out that while modern patterns and tooling go a long way, they you still need to put effort into making quality software of any kind.