View and Fill

Document Viewer on Linux or Chrome browser allow filling, if format is fillable
XFA standard was discontinued [1]. Now it's AcroForms
If form is not fillable, can still fill it with DocHub - which allows you to import PDF and superpose text on it. Which is neat, because you can use a text editor over a PDF.
- Dumb way to do this would be to use a Google Presentation with image of text, and superposing text in Google Presentation

Generating

LibreOffice Writer can create forms like this [2]
- Simply go to: view->toolbars->Form Controls.

Then simply drag and drop text box, heck mark, others. Transparent.
Use PDF save button, it exports and works. When filling, text is small, after filled, text gets larger and properly sized.
Check out the source files - odt and PDF. Can edit odt in LibreOffice Writer fully - text and fields. Can fill in fillable parts in Dochub on google drive. Can edit the text, but not fillable boxes, in Google Docs. TLDR; universal editability of PDF, but source editability only in LibreOffice Writer. Once exported into Google Docs, and saved, editability of fields is lost in LibreOffice. In short, use LibreOffice to edit the overall document. Use any software to fill.