Astro brings a friendly UI to maintain and update the sites? Like the WordPress panel and editor.
Many medium businesses don't even need that btw. In many instances marketing people just want to have control over websites, that they should not be given control over, since they usually are incapable of knowing the impact of what they are doing, when they add something like Google tagmanager to their site. They also tend to often break things, when using Wordpress, because they do not understand how it works under the hood, so that side of things is also not without hassle. And then the devs are called to fix what marketing broke. Even with Wordpress. At that point it would often be easier to let the devs build a non-Wordpress site, and any ideas about things that are not just content in markdown files need to be requests for the dev team to evaluate, and possibly work on, when deemed safe and lawful.
Sadly the power dynamics in businesses are often stacked against conscientious developers.
Have you ever worked with any SMBs before? This is at least 5 technical levels above their head. Would make as much sense as telling them, "just use this CLI tool".
We're talking about people who will email you from their phone that the website is down, but it turns out it's just their home internet that is down.
Or think that the website disappeared from the internet. When in reality it's now the #2 result in google and they never knew they you could type a URL directly into the browser.
A WP deployment on a simple shared hosting plan like that could run itself without needed a dev or sysadmin.
Maybe in some cases but that hasn't been my experience at all (or the experience of all the devs I know IRL).
Just a couple of weeks ago one of my clients installed a plugin which didn't allow users to log in.
And then come the legal fees for making the site actually conforming with the law, such as GDPR. Those fees are increased, because of people wanting to do stuff they need to declare to visitors of the site, for which they want reassurance, that all is well.
And then come the costs for paying a dev anyway, to fix things that they break or that become broken over time.
So no, 9.99$/month are very very far from a realistic price these businesses pay.
I'm not saying WP is great. Taking over a WP project from someone else can be daunting in tech debt and weird choices. But in terms of having a simple brochure website for businesses that get < 10k weekly visitors, it's pretty quick, cheap, and easy.
No real maintenance? So either you let your PHP version and plugins become outdated, or you sooner or later have to fix things breaking. Maybe you simply did not notice any breakage, because you don't do maintenance for customers?
A brochure website? Does that mean people enter their e-mail to be sent a brochure? (Then paragraph 1 applies again) Or brochure meaning, that you merely display information on pages and that's it?
I think for small info sites what you describe can be true, but for anything slightly larger not, especially not for small businesses.
Eg. https://www.gatsbyjs.com/docs/glossary/headless-wordpress/