Why do most photographers use Lightroom now, instead of, say, Photoshop?

I think this is for several reasons. One: we are photographers. Photoshop is excellent for illustrators who spend all day on one image, we spend time shooting and getting it right in camera, broadly, and then having to deal with many images. This is one area in which Lightroom shines.

Second: LR is easy to learn.

Third: LR works the way you work. Not the other way around. Your files can be wherever you like. And so on.

Fourth: did I mention its speed when you are dealing with many images?

Look at this example of an image:

Needs perspective correction. So.. a trip to DEVELOP module, and within that the LENS CORRECTION pane, and in that, click on AUTO:

That instantly gets me this:

Wow.

Of course it does not always work this well, this quickly, but even when manual intervention is needed, it’s still very, very quick.