There will always be bad things people look back on and hate but that doesn't mean there won't also be bad things people look back on and get nostalgia for. Non-media query adapting layouts, janky scrolljacking pages, an over-abundance of CSS transition/animation effects come to mind. I'm sure there will be plenty to look back on. E.g. people don't look back at the 2000s web and only think pop up ads, flash vulnerabilities, and browser crashes.