A few days ago someone reported here that they lost their tabs because the Restore feature failed when they opened Brave. They had 7000 tabs. If the automatic memory saver can handle 7000 tabs then we don’t need manual intervention, and if we do have a method for manual intervention it is essentially useless when someone has 7000 tabs.
Furthermore, if the Restore feature is not 100% secure then having a way to enable users to maintain 7000 tabs is actually detrimental to the user experience. Bookmarks are a more viable alternative, and can be exported whereas the tab strip cannot.