#1 complaint on every platform, for me. Sticky is very bad. Disappearing on scroll down but reappearing on scroll up is even worse. Just let the things scroll off screen, I can scroll to the top if I want to see anything on the header (spoiler alert: I won't). Old-school sticky sidebars (as in old frame layouts, for example) were totally fine on desktop, but are out of fashion now because they don't translate well to mobile.

I remove sticky elements with the dev console on anything I actually want to read that's longer than a few lines of text—though I can't do that on mobile, so it's worse there.

Excellent point, I completely forgot about those. Will add them now!

My Safari Bookmarklet to kill stickies: javascript:(function()%7B(function%20()%20%7Bvar%20i%2C%20elements%20%3D%20document.querySelectorAll('body%20*')%3Bfor%20(i%20%3D%200%3B%20i%20%3C%20elements.length%3B%20i%2B%2B)%20%7Bif%20(getComputedStyle(elements%5Bi%5D).position%20%3D%3D%3D%20'fixed')%20%7Belements%5Bi%5D.parentNode.removeChild(elements%5Bi%5D)%3B%7D%7D%7D)()%7D)()

My other one to re-enable proper scroll and zoom: javascript:document.queryselector('meta%5bname=viewport%5d').setattribute('content','width=device-width,initial-scale=1.0,maximum-scale=10.0,user-scalable=1');

These two can fix a lot of broken "responsive" garbage the front-end web dev community seems to really enjoy.