As Firefox is by far my most used app, I find that bookmarking the current tab and describing the task with no more than a few words or even as little as a few chars, to be a good way to keep track of what things I need to do soon. For things I would get to later or whenever I feel like it, I’ll put them in Firefox’s “Boookmarks Menu” or “Other Bookmarks” folders, and have lots of folders consisting of Reddit posts and searches about different topics.
I’ve been doing so for decades. I also use it to save recipes, which is a terrible idea because they tend to disappear eventually.
If you like playing with Bookmarks then i strongly recommend Tab Stash extension, I used to use it from the side bar, but when I discovered it can be opened as a tab, it’s has become the first tab I open in every session
So to answer your question, yes I do use Bookmarks as a To do Tomorrow, To view later, To Researcher in the future… Etc
Normally, I would respond that I don’t do that, because I keep forgetting about those bookmarks, but now you’ve reminded me that I did pin something there last week …and then promptly forgot about it. 🙃
I use a kanban board that I made in HTML and CSS as a to-do list when I need one. I should host it somewhere and bookmark but eh, it works as is.