You find PDFs easy to edit? Also, there's no reason why you can't make a single HTML file the way you make a single PDF file. It's not done in the web for organization and optimization reasons, but it's still possible.

Also, what do you mean about resizable? Open a web browser, adjust the width. Look at the text. Watch as it moves. Do that with a PDF, absolutely not the same. PDFs have a static size.

Form filling with HTML is easy too. https://www.w3schools.com/html/html_forms.asp