PHP 5 was released 16 years ago and was a massive evolution of the language. The same is true for PHP 5.2, 5.3, and 7. It's safe to say that your conclusions about the language are no longer accurate.
> Is there anything that PHP is developing or adopting that can not be had at other established languages?
No. I can't think of any reason to start a new project with PHP today. All of its best features are things that have been available in other languages for years. It's also not particularly popular outside of WordPress.