Stock photography exists to fill a gap when real photos aren't available, and it's used on far more small business websites than it should be. The problem isn't that stock photos look bad. It's that they actively work against the one thing a small business website needs to prove: that this is a real, specific business, not a template.
The photo has probably been seen before
A popular stock photo of a contractor, a smiling customer, or a generic clean kitchen shows up on dozens or hundreds of other business websites, sometimes competitors in the same city. A visitor who's shopped around doesn't consciously register "I've seen this photo before," but the sense of sameness registers anyway.
It signals effort wasn't spent where it should have been
A visitor evaluating whether to trust a contractor with their home is, consciously or not, reading the whole site as evidence. A generic photo where a real one should be reads as a shortcut, and shortcuts on a website raise quiet doubts about shortcuts on the job.
Real photos, even imperfect ones, outperform it
A slightly imperfect phone photo of an actual finished job, taken by the business owner, does more convincing work than a polished stock image, because it's proof rather than illustration. See phone photography tips for showing off finished work.
There are a few defensible uses
A background texture, an abstract decorative element, or a genuinely generic supporting graphic that isn't standing in for proof of work is a reasonable use of stock imagery. The problem is specifically using it to represent the business's own team, work, or customers.
What to do if you don't have enough real photos yet
Start collecting them now, on every job, going forward. See how many photos does a website actually need? for a realistic target, and treat a temporary gap as temporary rather than a permanent design choice.
Questions
Is it ever okay to use a stock photo of a person?
Only in cases where the image clearly isn't claiming to represent an actual member of the business, and even then, it's worth asking whether the content is really necessary at all.
What if my business is brand new and has no finished work yet?
Photograph the process, the setup, the equipment, anything real, rather than filling the gap with stock images of unrelated finished work. Real and in-progress beats fake and finished.
Do visitors actually notice stock photos consciously?
Not always consciously, but recognition and a sense of generic sameness both work below conscious awareness and still affect trust, even when a visitor can't say exactly why a site feels less credible.