Landscape on mobile is the least well supported configuration I know. Static headers/footers commonly take 50% or more vertical space with no way to dismiss or shrink them.

It's a bookmarklet that gets rid of sticky elements. It nukes those stupid fucking headers and footers and kills most cookie banners and "give me your email" type pop-ups. Works in every browser (I use it in Safari on iOS and Firefox on desktop). I almost reflexively go hit this bookmarklet on every website now. It makes the web so much better.