I'd argue that's true for all of PHP. Sure it got better, but compared to other langugaes it is still a mess.
I hope you can give some factual arguments why it's still a mess.
Wordpress has a lot to answer for here, but given the archaic and frankly idiotic way they operate they'll do nothing of the sort.
PHP is very backwards friendly and with a strong and stable ecosystem built around composer theres no excuses for majorly used (and often very profitable) wordpress plugins lagging so far behind.