You need to use a third party service or setup.
> Yes, but adding further content types at the level of code or these plugins is easy, trivially so.
Compared to what? Drupal? CraftCMS? Joomla? Where you go to a UI and do it all, versus installing a plugin with it's own quirks or using functions.php which ends up being the last place you want to touch after your done?
> It has several caches that are very powerful indeed, including those included by default. PHP is a theming engine.
No it doesn't, you need a plugin like W3 Total Cache. On their Cache page they tell you to use a plugin. https://wordpress.org/support/article/optimization-caching/
The other caching setups Opcache, Varnish are either integrated in PHP or a completely different service.
PHP is not a theming engine. Blade, twig, etc are theming engines.
> I mean, people use it to run newspapers, so not sure if this is true. It depends what you need.
Newspapers are glorified blogs, so yes that makes sense that they run on WordPress.
But the problem isn't random sites use WordPress, the problem is people build weird monstrosities on top of a really garbage system.