notes how WordPress lags behind minimum required PHP versions
and offers an explanation:
"Automattic never seemed to have an interest in PHP, the ecosystem or the broader community even though they are the stepping-stone into PHP development for many people."
has upped its minimal version to 7.2, Alexander feels it was an overly conservative choice:
"Instead of trying to push the adoption of “modern” PHP, they move to something people are already using. In my opinion, the right move would have been to move to PHP 7.4 now."