In my case, yes. It’s the only way I ever look at images, and I often use it to have a quick look at scripts or text/data files (try it on a CSV and it’ll show as a table!). It’s also convenient for design files, whose apps are incredibly slow to launch. With Alfred[1] you can even preview URLs directly.
Finally, QuickLook shines when you have file formats for which you don’t have an editor (e.g. you may need to view a Photoshop or Word document once in a while). It allows you to view them faster than in the editing application, for free, without having to install or configure anything.
Unlike the swath of people who are singing praises to Preview, I rarely touch it and mostly resort to QuickLook, even for PDFs.
> And then just for files you're just consuming, or does it also work for editing?
It works (at least) to edit images like Preview (annotate, rotate, crop).
That little "wait is this the file I want to open / overwrite?" When saving a file, it adds to an overall feeling of polish.
Like a tasty meal, it's all in the details and how they add up
So I'm probably missing something. Does that mean that, because it's so fast and low-effort, you use it as a complete replacement of a native app you'd use otherwise? And then just for files you're just consuming, or does it also work for editing? And what kind of files?
Note that I'm not out to prove any point, I just want to understand what I'm missing :)