I install the "Undistracted" extension in all of my Brave instances. In addition to having the ability to block arbitrary URLs it has many site-specific options like blocking YouTube recommendations or the LinkedIn timeline, all of which I ruthlessly enable. You can also set it to only work on certain days and times of the week. It's immensely useful.

I also pay for Kagi which has the ability to block certain domains from results. I'd imagine that blocking Instagram, Reddit, Youtube, etc. would also prevent rabbit-holing.