Had a discussion about this style with an illustrator friend a few months ago.
Illustration is genuinely better at conveying concepts than photography, and everyone is tired of lightbulbs, puzzle pieces, people in suits shaking hands and other stock photo cliches.
Problem is, commissioning an illustrator, especially a good one, is expensive and time consuming and takes excellent art direction to get right.[1]
This style however, is cheap, easy (anyone with a bit of drawing ability can do it), it’s sort of cozy and friendly, and doesn’t have any real negative cultural associations. It also wasn’t, until about six months ago, so totally overexposed it’s become a cliche in itself.
Now, there’s no excuse to use it - just betrays a fatal lack of originality. Might as well include an image of someone reaching up to a blue wireframe globe superimposed with zeroes and ones and @ symbols.
[1] Original illustration isn’t used nearly as much as it could or should be in digital products. Nautil.us do it well, but they are a magazine. Seriously, commission more illustration, it’s great.