Anecdote: we contracted a web page, and the guy started saying "it would be a Wordpress. It has very bad press, but it's because it is widely used". Ok, we start developing in the latest version of php, and soon he say "we have to go down a couple phpversions, because x pluging don't work in the latest". Requested version had a dozen critical CVEs. Plugin in question did something really basic, like a preview card with OpenGraph data, or something like that. Something a junior could code in a day.

And that is insecure Wordpress: people lego-mounting sites without touching code, only with plugins.