On the topic of bad modern UX in browsers: unloading tabs.
Now, I don't have a problem with the idea of saving up space for RAM. But whoever decided: oh we'll just delete the tab entirely and re-fetch it from the server was a moron.
Unloaded tabs should be cached to disk and then reload *from the disk*. I should not open a tab on a phone, go into airplane mode, then hours later find out that it's no longer accessible.