What do you hate most about modern websites?

Cookie consent popups are terrible, but a necessity because cookies are abused. I hate the abuse and take them as a hint a website isn't behaving properly.

Endless scrolling is terrible in my opinion. It may have an advantage for the dumbest form of consuming, but it is bad for any other use case.

But the worst is still overall tracking. I have accepted bootstrapped throwaway pages, they are seldom informative in any way. But the effort for tracking users is insane and invasive.

Autoplaying videos. Especially when places in "popup" boxes that follow you down the page.

a) Usability is still a challenge. b) Lack of personalisation c) Lot of unnecessary clutter.

Weight and latency over poor connections, single page apps requiring client side javascript (real time means nothing (good) to me). Surveillance capitalism and all that entails: no I don't want to share ANY thing with you.