When objects were first introduced in PHP 4, the implementation was essentially an array with function references and was horribly problematic. The fundamental problems of that implementation were thankfully addressed with the release of PHP 5, featuring an entirely rethought object implementation. In the versions that have come since, up through version the current 7.4 releases, numerous interesting language features for object-oriented programming (OOP) have emerged.
I suspect you're narrowing the scope of what this article was intended to cover. It is not just a look at PHP 7.4; it's just using the recent PHP release as an excuse for a look back at the history of the language:
With PHP 7.4.5 released in April, it's worthwhile to take a look at modern PHP, how it has evolved to address the criticisms of the past, and what lies ahead in its future.