Unsplash has become a fantastic resource of images: the quality of the photos is better than stock photo sites, and all of them are completely free of charge. I have been seen it growing from a static page with 1 free image a week which took forever to download into what it is today.
My stock photo use has dropped dramatically over the past years: I use fewer images (increasingly preferring simply bold typography), and if I use them, I either select "real" images of an actual product, store, city, or, I use Unsplash.
I am not the only one who has discovered this, and we now see the same thing happening as with stock photo sites 5 years ago: next to stock photo celebrities (this call centre rep for example), we now get Unsplash celebrities.
The 4 image above are contributed by rawpixel.com, which added many other images as well which are not (yet) as recognisable as these 2 "business people".