Think of a simple landing page with a form to save data from a form and send out an email with confirmation.
In PHP you just need to add to your HTML page a few lines of PHP code and copy it using scp to any share server hosting that costs 4 dollars a year.
No "automation", no "cloud", no REST APIs, no WSGI/Gunicorn, etc. just plain Apache with mod_php enabled, which is available everywhere. I don't think anything can beat PHP productivity for such simple usecases.
Aren't there a zillion online services that provides that product out of the box, most likely for free, only requiring a browser and some monkey clicks around? -> No PHP, HTML or web server.
As someone who works with PHP reasonably often, I'd say you have a very limited view of what PHP is actually used for in 2020, if you think 3 hosted blog services will replace it.
The majority of PHP usages tend to be, frankly, unsophisticated Wordpress, WooCommerce, Magento, and Drupal sites that are hacked up to support e-commerce. These needs can now be met by a vast array of ecom and omnichannel platforms.
In PHP you just need to add to your HTML page a few lines of PHP code and copy it using scp to any share server hosting that costs 4 dollars a year.
No "automation", no "cloud", no REST APIs, no WSGI/Gunicorn, etc. just plain Apache with mod_php enabled, which is available everywhere. I don't think anything can beat PHP productivity for such simple usecases.