Discussion on: Using fetch() and reduce() to grab and format data from an external API - A practical guide

I'm sure there are some super awesome things you can do with reduce() but the examples given just seem to provide the same functionality as a foreach loop?

$cityJobsData = json_decode(SOME_JSON, true);
$agencyFrequency = array();

foreach($cityJobsData as $city) {
    $agency = $city['agency'];

    if(!isset($agencyFrequency[$agency])) {
        $agencyFrequency[$agency] = 0;
    }
    $agencyFrequency[$agency]++;
}

Is there a reduce() example you could give that could not be easily accomplished with a foreach or ends up being significantly more readable than the equivalent foreach loop? I'm primarily a php developer that is just getting into doing more serious javascript past basic jquery/dom stuff, so excuse me if I'm missing something.