I agree.
But I also doubt this feature request will ever be addressed.
The pdf is not generated by Anvil code. Anvil simply asks the browser (one on the server, not yours) to render the pdf with the content of a form. So, the management of headers, footers, page numbers etc., it’s either done by the browser or it doesn’t just show up automagically because Anvil says so.
They could create a library specialized in creating pdf files, but those libraries already exist and you are already free to use them with Anvil.
Here is one attempt at managing footers that I have done, with the documentation of when it doesn’t work: Printing to PDF with good header and footer