As the sidebar is currently being updated, I thought of a recommendation rather than waiting for the Customize Sidebar add-on to be updated. It’s a relatively simple add-on, but incredibly nice to have. I personally really like the ability to collapse all decks and all note types, since I primarily use the tags (and I have a TON of note types and rarely need to click on them in the browser). The other changes such as the ability to show leech, marked, suspended, flags and today are also really handy for someone that likes to click on a tag, then shift click other things for a better filter.
I don’t mind waiting for the add-on to be updated, but with all the changes currently being made to the sidebar currently, I figured I would make the recommendation that this be officially integrated into anki