OK.

But what if i create booking forms or other non-static content?
This means finding new ways to generate the data back in WP.

That makes no sense at all.

First we had html and

Then dynamic languages. PHP, Javascript ...

Then CMS - in this case WordPress. With a bit of caching and code optimization, a WP page can be very fast.

Yeah and today?
html, javascript (unlimited frameworks), css (unlimited frameworks), node.js, webpack, graphql, CLI without end, etc.

What do we do with it?
We first build a WordPress page and then we pack the whole thing again in a framework to Gatsby and then pack Markdown again.

Unfortunately that makes no sense at some point.

To build a simple landing page you need html and css.
Not more. Hardly anyone can still build a website with these simple tools today.

It's crazy what Web development comes up with to find fewer and fewer solutions that are simple.