WordPerfect didn't use HTML for formatting, because HTML hadn't been invented yet. But it did use its own set of formatting tags, which are more or less analogous. And it had a "Reveal Codes" key you could press at any time to show all the formatting tags that were active in the current document, letting you tweak their placement, add new ones by hand, etc. You could always get directly at the logic that was being used to format your document.

Word's big selling point was that, being Windows-based, it could abstract all that complexity away and let you format documents entirely visually. And it worked! Or at least, it worked well enough for most people most of the time. But the problem with Word's approach has always been that, when it doesn't work, it can be incredibly frustrating to figure out exactly why. Which was never a problem with WordPerfect, since there was no layer of hidden formatting magic sitting between you and your document.

It also helps to turn on the display option "Show all formatting marks". That way you can kind of see the objects and boundaries. Even though you can't directly manipulate those markers like tags in TeX or something they still give helpful clues as to what's happening.

(I'm not trying to defend the usability problems in Word, just pointing out some ways to live with them.)

Neither can you really use min-height=20mm. A pity. And the nicer pdf creators (weasyprint) don't understand the new css rules like flexbox or grid.

So we are still stuck. No easy way to force a footer to the end of a printed page via css.

Aren't margin boxes the way to go for page footers and such?

edit: This page recommends PDFreactor, which seems to support at least flexbox https://print-css.rocks/tools.html#pdfreactor