Personally, I can’t use bookmarks because if they’re out of sight, they get forgotten. Keeping things in an open tab is like having the browser constantly bugging me to remind me that I have to do this thing. It doesn’t guarantee that it gets addressed in a timely manner, but with the alternative it’s guaranteed to not be done at all.

It also helps to keep my place in my work. There’s things that I’ll always have open because I need quick access to them and don’t want the friction of trying to find the page to lead to procrastination. Same with anything that’s relevant to work in progress.